Travis: Adding fish-2.2.0 from github.

Adding apt dependencies + build script + cache directive.

.travis.yml

@@ -5,13 +5,28 @@ sudo: false
 addons:
   apt:
     packages:
+    - bc
+    - doxygen
+    - expect
+    - gettext
+    - libncurses5-dev
     - tree
-    - fish
+
+env:
+  global:
+    - PATH="$HOME/fish/bin:$PATH"
+
+before_install:
+  - tests/install_fish.sh
 
 before_script: pwd; tree -h
 script: "/bin/sh bin/install"
 after_script:
-- cd ~/.config/fish; tree -h; find . -type f | xargs cat
+  - cd ~/.config/fish; tree -h; find . -type f | xargs cat
+
+cache:
+  directories:
+    - $HOME/fish
 
 notifications:
   email:

tests/install_fish.sh

@@ -0,0 +1,10 @@
+#!/bin/sh
+set -e
+# check to see if fish bin doesn't exist
+if [ ! -x "$HOME/fish/bin/fish" ]; then
+  cd /tmp
+  wget -O - https://github.com/fish-shell/fish-shell/releases/download/2.2.0/fish-2.2.0.tar.gz | tar xzv
+  cd fish-2.2.0 && ./configure --prefix=$HOME/fish && make -j2 && make install;
+else
+  echo 'Using cached directory.';
+fi