Add hemisu.vim color scheme.

Looks good on Mac OSX Terminal.app; original source:
https://github.com/noahfrederick/Hemisu
Gary Bernhardts (destroyallsoftware.com) colorscheme grb256
add gruvbox
detailed, frood, and kyle added
Added simple install to README.md
Update README.md

Very simple install
Add correct working railscasts colorscheme
Added bubblegum.vim
Added getfresh.vim
Added luna.vim
Adding tomorrow night theme
jiks.vim: a mod of vividchalk
Added flatland colorscheme
Update codeschool.vim

g:colors_name should point to a valid color scheme file.  Fixing.

`Error detected while processing /Applications/MacVim.app/Contents/Resources/vim/runtime/syntax/synload.vim:
line   19:
E185: Cannot find color scheme 'Code School 3'`
Merge pull request #14 from simonsj/master

Add hemisu.vim color scheme.
Merge pull request #15 from chrokh/master

Adding Gary Bernhardts (destroyallsoftware.com) colorscheme grb256, based on ir_black
Merge pull request #17 from notice501/master

add gruvbox
Merge pull request #18 from taylor/master

detailed, frood, and kyle added
Merge pull request #34 from thebitguru/master

Fix an error in codeschool.vim
Merge pull request #33 from z0rch/master

Added flatland colorscheme