chore(deps-dev): bump lerna from 3.18.4 to 3.19.0 (aws#5139)

Bumps [lerna](https://github.com/lerna/lerna/tree/HEAD/core/lerna) from 3.18.4 to 3.19.0.
- [Release notes](https://github.com/lerna/lerna/releases)
- [Changelog](https://github.com/lerna/lerna/blob/master/core/lerna/CHANGELOG.md)
- [Commits](https://github.com/lerna/lerna/commits/v3.19.0/core/lerna)

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

Author: dependabot-preview[bot]

package.json

@@ -21,7 +21,7 @@
     "jest": "^24.9.0",
     "jsii-diff": "^0.20.7",
     "jsii-pacmak": "^0.20.7",
-    "lerna": "^3.18.4",
+    "lerna": "^3.19.0",
     "nodeunit": "^0.11.3",
     "nyc": "^14.1.1",
     "standard-version": "^7.0.1",