Move mockdate to devdependencies

Author: rmosolgo

package-lock.json

@@ -59,7 +59,6 @@
     "lodash": "^4.17.19",
     "mini-css-extract-plugin": "^0.9.0",
     "mkdirp": "^1.0.3",
-    "mockdate": "^3.0.2",
     "morgan": "^1.9.1",
     "node-fetch": "^2.6.1",
     "parse5": "^6.0.1",
@@ -123,6 +122,7 @@
     "make-promises-safe": "^5.1.0",
     "mime": "^2.4.4",
     "mock-express-response": "^0.2.2",
+    "mockdate": "^3.0.2",
     "nock": "^13.0.4",
     "nodemon": "^2.0.4",
     "npm-merge-driver-install": "^2.0.0",