remove Brewfile and add brew install script

* rename tools/ to scripts/
* create brew.sh for brew installation
* move osx.sh to scripts/
* +x install.sh

scripts/install.sh

@@ -0,0 +1,10 @@
+echo "cloning repo to ~/.dotfiles"
+git clone git@github.com:nicknisi/dotfiles.git ~/.dotfiles
+cd ~/.dotfiles
+echo "initializing git submodules"
+git submodule init
+git submodule update
+echo "running backup"
+rake backup
+echo "creating symlinks"
+rake install