Restrict dev dependency versions to known working ranges

Mocha v4 broke nyc coverage hooks and caused CI to hang/fail.

package.json

@@ -16,10 +16,10 @@
         "coveralls": "^2.13.1",
         "express": "~3.4.2",
         "grunt": "^0.4.5",
-        "grunt-bumpx": "latest",
-        "mocha": "latest",
-        "nyc": "^11.2.1",
-        "sinon": "latest"
+        "grunt-bumpx": "^0.2.1",
+        "mocha": "^3.5.3",
+        "nyc": "^3.2.2",
+        "sinon": "^4.0.1"
     },
     "repository": {
         "type": "git",
@@ -32,7 +32,7 @@
     ],
     "license": "MIT",
     "scripts": {
-        "test": "nyc --reporter=lcov --reporter=text mocha && (if [ -n \"$TRAVIS\" ]; then cat ./coverage/lcov.info | coveralls; fi)",
+        "test": "nyc --reporter=lcov --reporter=text mocha && (if [ -n \"$TRAVIS\" ]; then cat ./coverage/lcov.info && cat ./coverage/lcov.info | coveralls -v; fi)",
         "test:quick": "mocha"
     },
     "engine": {