Add a delay after pushing a new tag before trying to create a GH release (#78)

Avoid an issue where trying to create a GH release immediately after
pushing the tag often fails.

package.json

@@ -142,7 +142,7 @@
     "test": "gulp test-app",
     "preversion": "npm run test",
     "version": "make clean all && ./scripts/update-changelog.js && git add CHANGELOG.md",
-    "postversion": "git push && git push --tags && ./scripts/create-github-release.js",
+    "postversion": "./scripts/postversion.sh",
     "prepublish": "npm run-script build"
   }
 }

scripts/postversion.sh

+#!/usr/bin/env sh
+
+SCRIPT_DIR=$(dirname `readlink -f "$0"`)
+
+git push
+git push --tags
+
+# Wait a moment to give GitHub a chance to realize that the tag exists
+sleep 2
+
+$SCRIPT_DIR/create-github-release.js