Add Checkout Previous Branch to git til.

README.md

@@ -9,6 +9,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 
 ### git
 
+- [Checkout Previous Branch](git/checkout-previous-branch.md)
 - [Intent To Add](git/intent-to-add.md)
 - [Staging Changes Within Vim](git/staging-changes-within-vim.md) 
 - [Stashing Untracked Files](git/stashing-untracked-files.md)

git/checkout-previous-branch.md

@@ -0,0 +1,13 @@
+# Checkout Previous Branch
+
+Git makes it easy to checkout the last branch you were on.
+
+```bash
+$ git checkout -
+```
+
+This is shorthand for `git checkout @{-1}` which is a way of referring to
+the previous (or last) branch you were on. You can use this trick to easily
+bounce back and forth between `master` and a feature branch.
+
+[source](http://stackoverflow.com/questions/7206801/is-there-any-way-to-git-checkout-previous-branch)