additional tmux aliases
Fix chruby plugin to not complain if chruby is *not* installed
Throw an error message when $WORKON_HOME is not set

Took me a while to figure this one out, and I have a default installation of virtualenvwrapper -- this is a soft fix, just put an error message. But perhaps the fix should be to use the default value `~/.virtualenvs`.
Fixed output issues webith websearch plugin.

- if user has rm set as an alias to 'rm -i' user is prompted to whether to
  remove the nohup.out file.

 $ ddg fools
	nohup: ignoring input and appending output to ‘nohup.out’
	rm: remove regular empty file ‘nohup.out’?

- if output redirected to a file nohup will not create nohup.out and rm is
  unecessary.
Added Yii2 command completion
Add yii2 readme
mira theme shows active node, ruby and java versions
added node- before node version for consistency
Updated Yii2 command completion
Merge pull request #3397 from peteches/master

Fixed output issues webith websearch plugin.
Merge pull request #3352 from benjaoming/virtualenvwrapper_workon_unset

Throw an error message when $WORKON_HOME is not set
Merge pull request #3338 from eripa/chruby_fix

Fix chruby plugin to not complain if chruby is *not* installed
Merge pull request #3146 from typekpb/tmux-aliases

additional tmux aliases
Merge pull request #3404 from ekaragodin/master

Added Yii2 command completion
Merge pull request #3407 from rawberg/mira-theme

mira theme shows active node, ruby and java versions
Add CONTRIBUTING.md file general structure
Categories of issues in oh-my-zsh (work-in-progress)
Format categories of issues in oh-my-zsh (still WIP)

Conflicts:
	CONTRIBUTING.md