Update dependencies.

Author: tmpfs

package.json

@@ -21,12 +21,12 @@
     "zephyr": "^1.3.6"
   },
   "devDependencies": {
-    "browserify": "~13.0.0",
-    "chai": "~3.5.0",
-    "coveralls": "~2.11.9",
+    "browserify": "^16.2.3",
+    "chai": "^4.2.0",
+    "coveralls": "^3.0.2",
     "istanbul": "~0.4.3",
-    "mocha": "~2.4.5",
-    "moment": "~2.12.0"
+    "mocha": "^5.2.0",
+    "moment": "^2.22.2"
   },
   "scripts": {
     "lint": "jshint . && jscs .",