Build latest vim quickly from git mirror.

* Run tests against latest vim & stock.
* Fixes #201

.travis.yml

@@ -1,9 +1,23 @@
 language: vim
+rvm:
+  - 1.8.7 # Use stock
+  - 1.9.2 # Build latest
 
-install: |
-  sudo apt-get update
-  sudo apt-get install vim
+before_script: |
   cd ..
+  if [ $(ruby -e 'puts RUBY_VERSION') == '1.8.7' ]; then
+    sudo apt-get -y update
+    sudo apt-get -y install vim
+  else
+    git clone --depth 1 https://github.com/vim/vim
+    cd vim
+    ./configure --with-features=huge
+    make
+    sudo make install
+    sudo rm /usr/bin/vim
+    sudo ln -s /usr/local/bin/vim /usr/bin/vim
+    cd -
+  fi
   git clone https://github.com/godlygeek/tabular
   git clone https://github.com/junegunn/vader.vim