Bump lodash from 4.17.4 to 4.17.15

Bumps [lodash](https://github.com/lodash/lodash) from 4.17.4 to 4.17.15.
- [Release notes](https://github.com/lodash/lodash/releases)
- [Commits](lodash/lodash@4.17.4...4.17.15)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -19,7 +19,7 @@
   "dependencies": {
     "basic-auth": "1.1.0",
     "bluebird": "3.7.2",
-    "lodash": "4.17.4",
+    "lodash": "4.17.15",
     "promisify-any": "2.0.1",
     "statuses": "1.3.1",
     "type-is": "1.6.15"