glyph tag renders <i> element by default, set tag option otherwise
update documentation for glyph helper
Merge branch 'master' of github.com:seyhunak/twitter-bootstrap-rails into issue_718

* 'master' of github.com:seyhunak/twitter-bootstrap-rails:
  travis wants 1.9.3, 1.9.2 is complaining it can't install rubyracer.
  fix failed test
  green tests
  ran guard init
  added guard, pry, and rspec configuration for each
  fix command to travis
  command is spec not rspec
  fix travis command to run test
  update rake to run rspec
  drop travis ruby support for 1.8 and add 2.1
Merge pull request #753 from toadkicker/issue_718

glyph tag renders <i> element by default, set tag option otherwise