Add lodash as explicit dev dependency

lodash was already required for a number of other packages, such as babel. Now
it's also needed for the `isEqual` function.

Author: Elias Mulhall

package.json

@@ -67,6 +67,7 @@
     "colors": "^1.1.2",
     "cross-env": "^5.0.1",
     "jest": "^22.0.2",
+    "lodash": "^4.17.5",
     "prettier": "^1.4.4",
     "rimraf": "^2.6.1",
     "rollup": "^0.53.0",

yarn.lock

@@ -1917,7 +1917,7 @@ lodash.sortby@^4.7.0:
   version "4.7.0"
   resolved "https://registry.yarnpkg.com/lodash.sortby/-/lodash.sortby-4.7.0.tgz#edd14c824e2cc9c1e0b0a1b42bb5210516a42438"
 
-lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.4:
+lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.4, lodash@^4.17.5:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"