Restructure package.json to separate test deps from dev deps

package.json

@@ -34,6 +34,7 @@
   "dependencies": {},
   "devDependencies": {
     "autoprefixer": "^6.6.1",
+    "babel-core": "^6.0.0",
     "babel-eslint": "^7.1.1",
     "babel-loader": "^6.2.10",
     "babel-plugin-add-module-exports": "^0.2.1",
@@ -42,14 +43,12 @@
     "babel-preset-es2015": "^6.22.0",
     "babel-register": "^6.18.0",
     "babel-root-import": "^4.1.5",
-    "chai": "^3.5.0",
     "core-js": "^2.4.1",
     "css-mqpacker": "^5.0.1",
     "custom-event-polyfill": "^0.3.0",
     "del": "^2.2.2",
     "ecstatic": "^2.1.0",
     "eslint": "^3.14.0",
-    "eslint-plugin-mocha": "^4.8.0",
     "fastclick": "^1.0.6",
     "git-hooks": "^1.1.7",
     "gulp": "^3.9.1",
@@ -73,20 +72,10 @@
     "gulp-uglify": "^2.0.0",
     "gulp-util": "^3.0.8",
     "js-cookie": "^2.1.3",
-    "karma": "^1.3.0",
-    "karma-chrome-launcher": "^2.0.0",
-    "karma-coverage": "^1.1.1",
-    "karma-mocha": "^1.3.0",
-    "karma-notify-reporter": "^1.0.1",
-    "karma-sourcemap-loader": "^0.3.7",
-    "karma-spec-reporter": "0.0.26",
-    "karma-webpack": "^2.0.1",
     "lunr": "^0.7.2",
     "material-design-color": "^2.3.2",
     "material-shadows": "^3.0.1",
-    "mocha": "^3.2.0",
     "modularscale-sass": "^2.1.1",
-    "moniker": "^0.1.2",
     "node-notifier": "^5.0.0",
     "postcss-pseudo-classes": "^0.1.0",
     "stylelint": "^7.8.0",
@@ -101,12 +90,24 @@
     "yargs": "^6.6.0"
   },
   "optionalDependencies": {
+    "chai": "^3.5.0",
+    "eslint-plugin-mocha": "^4.8.0",
     "gemini": "^4.14.3",
+    "karma": "^1.3.0",
+    "karma-chrome-launcher": "^2.0.0",
+    "karma-coverage": "^1.1.1",
+    "karma-mocha": "^1.3.0",
+    "karma-notify-reporter": "^1.0.1",
+    "karma-sourcemap-loader": "^0.3.7",
+    "karma-spec-reporter": "0.0.26",
+    "karma-webpack": "^2.0.1",
+    "mocha": "^3.2.0",
+    "moniker": "^0.1.2",
     "sauce-connect-launcher": "^1.2.0",
     "selenium-standalone": "^6.0.0"
   },
   "engines": {
-    "node": ">= 4.5.0"
+    "node": ">= 5.0.0"
   },
   "private": true
 }