Bump lodash from 4.17.19 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.19 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.19...4.17.21)

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package.json

@@ -46,7 +46,7 @@
     "babel-preset-es2015": "^6.24.1",
     "diff": "^4.0.2",
     "growl": "^1.10.5",
-    "lodash": "^4.17.19",
+    "lodash": "^4.17.21",
     "minimist": "^1.2.5",
     "mocha": "^3.2.0"
   },

yarn.lock

@@ -2247,10 +2247,10 @@ lodash.keys@^3.0.0:
     lodash.isarguments "^3.0.0"
     lodash.isarray "^3.0.0"
 
-lodash@^4.17.10, lodash@^4.17.14, lodash@^4.17.19, lodash@^4.17.4, lodash@~4.17.10, lodash@~4.17.12, lodash@~4.17.5:
-  version "4.17.19"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.19.tgz#e48ddedbe30b3321783c5b4301fbd353bc1e4a4b"
-  integrity sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ==
+lodash@^4.17.10, lodash@^4.17.14, lodash@^4.17.21, lodash@^4.17.4, lodash@~4.17.10, lodash@~4.17.12, lodash@~4.17.5:
+  version "4.17.21"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.21.tgz#679591c564c3bffaae8454cf0b3df370c3d6911c"
+  integrity sha512-v2kDEe57lecTulaDIuNTPy3Ry4gLGJ6Z1O3vE1krgXZNrsQ+LFTGHVxVjcXPs17LhbZVGedAJv8XZ1tvj5FvSg==
 
 longest@^1.0.1:
   version "1.0.1"