Add patch for mocha test runner colors

See mochajs/mocha#1200 (comment)

_actions/mocha.diff

@@ -0,0 +1,12 @@
+--- _mocha
++++ _mocha
+@@ -1,3 +1,9 @@
++// Fix expected/actual colors with Solarized
++// https://github.com/mochajs/mocha/issues/1200#issuecomment-62780003
++var colors = require('../lib/reporters/base').colors;
++colors['diff added']   = '32;40';
++colors['diff removed'] = '32;40';
++
+ /**
+  * Module dependencies.
+  */

_actions/patch-mocha.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+_mocha=$(which _mocha)
+
+if [ ! -r "$_mocha" ]; then
+    # _mocha executable not present
+    exit
+fi
+
+if head -n 1 "$_mocha" | grep -q Solarized; then
+    # _mocha executable already patched
+    exit
+fi
+
+# resolve any symlinks in path to _mocha - otherwise patch will change _mocha
+# from a symlink to a regular file, and Node.js require will not work properly
+while [ -L "$_mocha" ]; do
+    pushd "$(dirname "$_mocha")" > /dev/null
+    pushd "$(dirname "$(readlink "$_mocha")")" > /dev/null
+    _mocha="$(pwd)/_mocha"
+    popd > /dev/null
+    popd > /dev/null
+done
+
+if [ ! -w "$_mocha" ]; then
+    # cannot write to _mocha executable
+    echo "WARNING: Failed to patch _mocha ($_mocha) - try this:"
+    echo "  sudo $0"
+    exit
+fi
+
+cd "$(dirname "$0")"
+patch --directory "$(dirname "$_mocha")" -p0 < mocha.diff