Revert npm version specifiers to ~ in package.json

Our Jenkins CI instances don't yet have the latest node and npm
available.

See: http://fredkschott.com/post/2014/02/npm-no-longer-defaults-to-tildes/

Signed-off-by: Alex Coles <alex@alexbcoles.com>

package.json

@@ -13,17 +13,17 @@
     "json2htmlcov": "~0.1.1",
     "exec": "0.0.6",
     "readable-stream": "1.1.11",
-    "karma": "^0.12.3",
+    "karma": "~0.12.3",
     "karma-coverage": "~0.0.3",
-    "karma-phantomjs-launcher": "^0.1.4",
-    "grunt-karma": "^0.8.2",
-    "mocha": "^1.18.2",
-    "karma-mocha": "^0.1.3",
-    "karma-chrome-launcher": "^0.1.3",
-    "karma-firefox-launcher": "^0.1.3",
-    "chai": "^1.9.1",
-    "karma-chai": "^0.1.0",
-    "karma-junit-reporter": "^0.2.2"
+    "karma-phantomjs-launcher": "~0.1.4",
+    "grunt-karma": "~0.8.2",
+    "mocha": "~1.18.2",
+    "karma-mocha": "~0.1.3",
+    "karma-chrome-launcher": "~0.1.3",
+    "karma-firefox-launcher": "~0.1.3",
+    "chai": "~1.9.1",
+    "karma-chai": "~0.1.0",
+    "karma-junit-reporter": "~0.2.2"
   },
   "scripts": {
     "test": "./node_modules/karma/bin/karma start --single-run --browsers Firefox,PhantomJS"