Add an ESLint rule to prevent additions of new `bind` usages in annotator/ code

Add a lint rule to ensure that new developers do not use `bind` in
annotator/ code. This only applies to first-party code. Third-party code
used in the annotation layer is still at-risk of being broken by old
`bind` polyfills.

src/annotator/.eslintrc.js

+'use strict';
+
+module.exports = {
+  rules: {
+    'no-restricted-properties': [2, {
+      // Disable `bind` usage in annotator/ code to prevent unexpected behavior
+      // due to broken bind polyfills. See
+      // https://github.com/hypothesis/client/issues/245
+      property: 'bind',
+      message: 'Use function expressions instead of bind() in annotator/ code'
+    }]
+  }
+};

src/annotator/test/annotation-sync-test.js

@@ -29,8 +29,8 @@ describe('AnnotationSync', function() {
     };
 
     options = {
-      on: emitter.on.bind(emitter),
-      emit: emitter.emit.bind(emitter),
+      on: emitter.on.bind(emitter), // eslint-disable-line no-restricted-properties
+      emit: emitter.emit.bind(emitter), // eslint-disable-line no-restricted-properties
     };
 
     publish = function() {