Update oh-my-zsh
Consolidate oh-my-zsh rails plugins
Remove vendored vim plugins
Ingnore vendored vim bundles
Update vundle
Add rbenv shims to path
Add docker alias and env
Add `git last` command to show diff of last commit
Remove `last_commit` alias
Include implicit ruby version in rbenv prompt

Show [explicit] and (implicit) ruby versions

An explicit ruby version is one set by running `rbenv local <ruby-version>`.

The implicit ruby version will show the rbenv global ruby version in
perentheses when it has not been set explicitly with `rbenv local`
Add additional colors for diffs