Add globals property to the environments.
Add rules per environments to config.
Removing jake, adding Grunt, Travis now runs grunt
Fixing indent in gruntfile
Add tests to config load order: base, env, user.
Merge pull request #390 from ilyavolodin/Grunt

Removing jake, adding Grunt, Travis now runs grunt (Closes #389)
Merge pull request #391 from albertosantini/issue-380

Fixes #380