Change from `sh` to `bash`

Interpolation of strings was behaving bad in line 28 of `install.sh`.
Add SigLevel = Never to Yaourt source repository
Fix PATH for gems in fresh installation
Rename `install.sh` to `provision.sh`

It's a better suited name.
Move `install` module to `site`

Docs on Puppet seem to prefer this name for entry points of catalogs.
Install httpie
Remove `images-for-README`

It's cluttering the repository. Images are now stored in Dropbox.
Fix typos and better formatting in README
Move gitgutter to proper place

Along with its fellows.
New snippets configs
Add snippet for Pry