Add package_json grunt task to update package.json

package.json contains a list of locale files, that was manually updated until
now. This PR adds a grunt task to update package.json and registers it to run
on release.

fixes #1766
Add a newline at the end of component.json
Convert 4 remaining languages to locale
Merge pull request #1807 from ichernev/fix-remaining-lang

Convert 4 remaining languages to locale
grunt-jscs-checker renamed to grunt-jscs
optimizing clone first cut
moar speed
Add test for momentProperties and cloning
Merge pull request #1808 from ichernev/optimize_clone

Optimize clone
Add bump_version grunt task
Add 2.8.0 changelog
Fix Tibetan language code (ti -> bo)
Fix Burmese code in comment (mm -> my)
Bump version to 2.8.0
Build 2.8.0
Fix travis npm version bug
Add failing unit tests asserting old moment().lang(str) behavior
Fix moment().lang() pre 2.8 behavior
Make jscs happy
Merge pull request #1813 from ichernev/bugfix/maintain-lang-original-behavior

Fix moment().lang([key]) backwards compatibility broken in 2.8.0.