Enhancements for templates testing

[sh19910711]

This pull request includes some enhancements for templates testing.

• Unify tests into the TDD style
• Use already installed phantomjs if it exists
  • if not, then install it automatically from the npm registry
• Use mocha-phantomjs-core instead of mocha-phantomjs
  • to use the latest version of phantomjs
• Test key events of the auto completion feature

Thank you.

[rails-bot]

r? @gsamokovarov

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[gsamokovarov]

Thanks!