Bump lodash from 4.17.4 to 4.17.15

### CVE-2019-10744
critical severity
Vulnerable versions: < 4.17.12
Patched version: 4.17.12

> Affected versions of lodash are vulnerable to Prototype Pollution.
> The function defaultsDeep could be tricked into adding or modifying properties of Object.prototype using a constructor payload.