Bump lodash from 4.17.11 to 4.17.21

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.11 to 4.17.21.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.11...4.17.21)

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

Author: dependabot[bot]

package.json

@@ -102,7 +102,7 @@
     "bootstrap": "4.0.0",
     "classnames": "2.2.5",
     "css-box-model": "0.0.13",
-    "lodash": "4.17.11",
+    "lodash": "4.17.21",
     "moment": "2.22.1",
     "react-beautiful-dnd": "2.6.2",
     "react-color": "2.13.1",