moved mocha to dev dependencies where it belongs

Author: makuro

package.json

@@ -33,7 +33,6 @@
     "inquirer": "^6.2.2",
     "js-yaml": "^3.12.1",
     "lodash": "^4.17.11",
-    "mocha": "^5.2.0",
     "nodemon": "^1.18.9",
     "serve-static": "^1.13.2",
     "swagger-converter": "^1.5.1",
@@ -43,6 +42,7 @@
   },
   "devDependencies": {
     "chai": "^3.5.0",
+    "mocha": "^5.2.0",
     "mock-stdin": "^0.3.1",
     "proxyquire": "^2.1.0",
     "should": "^13.2.3",