Add show section logic

- isFeatureFlagEnabled will be used to feature flag the groups-list
  template.
- When the community_groups feature flag is enabled, only show the
  groups drop down menu if there is more than one group present.
  This varies slightly from the current behavior where this only
  happens if it is a thirdparty account.
- Fix the group const names to follow js cammel case convention and
  use full groups rather than recreating them every time.

Only build client before publishing, not when running `yarn install`

Bump sinon from 7.2.6 to 7.2.7

Bump eslint from 5.14.1 to 5.15.0

Bump @octokit/rest from 16.16.2 to 16.16.3

Bumps [sinon](https://github.com/sinonjs/sinon) from 7.2.6 to 7.2.7.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v7.2.6...v7.2.7)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bump sinon from 7.2.4 to 7.2.6

Bump through2 from 3.0.0 to 3.0.1

Bump karma from 4.0.0 to 4.0.1

Bumps [sinon](https://github.com/sinonjs/sinon) from 7.2.4 to 7.2.6.
- [Release notes](https://github.com/sinonjs/sinon/releases)
- [Changelog](https://github.com/sinonjs/sinon/blob/master/CHANGELOG.md)
- [Commits](https://github.com/sinonjs/sinon/compare/v7.2.4...v7.2.6)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [eslint](https://github.com/eslint/eslint) from 5.14.1 to 5.15.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v5.14.1...v5.15.0)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [karma](https://github.com/karma-runner/karma) from 4.0.0 to 4.0.1.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v4.0.0...v4.0.1)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 16.16.2 to 16.16.3.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v16.16.2...v16.16.3)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [through2](https://github.com/rvagg/through2) from 3.0.0 to 3.0.1.
- [Release notes](https://github.com/rvagg/through2/releases)
- [Commits](https://github.com/rvagg/through2/compare/v3.0.0...v3.0.1)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Change the behavior where a production build of the client was triggered
whenever `yarn install` was run. Instead only create a prod build when
bumping the version or before publishing.

This mostly makes local development more convenient as it avoids
unnecessarily rebuilding the client after installing dependencies. It
will also speed up Travis builds slightly as Travis always runs `yarn install`.

Some Jenkins builds will be a little faster. Jenkins runs `make test`
directly, which only runs `yarn install` if dependencies have changed
since the last build. We may decide in future that Jenkins builds should always
do a prod build as part of the testing process. Currently the prod build
happens as part of the QA release step.

This commit also changes the version and publishing lifecycle scripts to
run the same commands. Previously they ran different commands without an
obvious reason for doing so.

Fix default logo rendering

The previous default rendering was broken because it was not escaping
the svg correctly so the svg is now wrapped in encodeURIComponent.

Load polyfills only in browsers that need them

Bump @babel/core from 7.3.3 to 7.3.4

Bumps [@babel/core](https://github.com/babel/babel) from 7.3.3 to 7.3.4.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/compare/v7.3.3...v7.3.4)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bump @octokit/rest from 16.16.0 to 16.16.2

Bump @babel/preset-env from 7.3.1 to 7.3.4

- Add group const which will be used in the current and new tests.
- Remove group links and reference the links through the new group
  const instead.
- Fix incorrect usage of groups and overriding of `fakeGroups.all`:
  `groups` is a const defined for all tests but some tests where
  making a new groups const or overriding the `fakeGroups.all` when
  they should have overridden the value of the `groups` const.

Bump mocha from 6.0.1 to 6.0.2

Bumps [@octokit/rest](https://github.com/octokit/rest.js) from 16.16.0 to 16.16.2.
- [Release notes](https://github.com/octokit/rest.js/releases)
- [Commits](https://github.com/octokit/rest.js/compare/v16.16.0...v16.16.2)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [@babel/preset-env](https://github.com/babel/babel) from 7.3.1 to 7.3.4.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](https://github.com/babel/babel/compare/v7.3.1...v7.3.4)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Bumps [mocha](https://github.com/mochajs/mocha) from 6.0.1 to 6.0.2.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](https://github.com/mochajs/mocha/compare/v6.0.1...v6.0.2)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Refactor polyfill bundling and loading to load only the polyfills that
are required for the current browser, and make it easier to load new
polyfills conditionally in future.

The polyfills are partioned into sets. For each set there is a separate
bundle, with an entry point in src/shared/polyfills/{set}.js. There is
an index file in src/shared/polyfills/index.js which defines functions
to test which sets are needed by the current browser.

This change prevents loading of ~246KB of minified JS (not gzipped) in modern
browsers which don't need any of the polyfills.

unorm is a large library which also exposes its functionality as a
`String.prototype.normalize` polyfill.

Using the native method is a first step towards not loading unorm in
browsers that have Unicode normalization available natively.

Bump autoprefixer from 9.4.8 to 9.4.9

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 9.4.8 to 9.4.9.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/postcss/autoprefixer/compare/9.4.8...9.4.9)
Signed-off-by: dependabot[bot] <support@dependabot.com>

Install wicked-good-xpath dependency from npm

This makes it easier to see what version we are using and get
automated notifications if the package is updated for any reason.

 - Update to current release of wicked-good-xpath from npm
 - Remove reference to IE 10 in comment since we now only support IE 11

Bump mocha from 6.0.0 to 6.0.1

Bump katex from 0.10.0 to 0.10.1