Add basic test cases for shell extensions (#83)

- Key bindings for bash, zsh, and fish
- Fuzzy completion for bash (file, dir, process)

.travis.yml

@@ -1,11 +1,15 @@
 language: ruby
+rvm:
+- 2.2.0
 
 install:
 - sudo apt-get update
 - sudo apt-get install -y libncurses-dev lib32ncurses5-dev
 - sudo add-apt-repository -y ppa:pi-rho/dev
+- sudo apt-add-repository -y ppa:fish-shell/release-2
 - sudo apt-get update
 - sudo apt-get install -y tmux=1.9a-1~ppa1~p
+- sudo apt-get install -y zsh fish
 
 script: |
   export GOROOT=~/go1.4