Bump js-yaml from 3.13.0 to 3.13.1 (#139)

Bumps [js-yaml](https://github.com/nodeca/js-yaml) from 3.13.0 to 3.13.1.
- [Release notes](https://github.com/nodeca/js-yaml/releases)
- [Changelog](https://github.com/nodeca/js-yaml/blob/master/CHANGELOG.md)
- [Commits](nodeca/js-yaml@3.13.0...3.13.1)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

package-lock.json

@@ -33,7 +33,7 @@
   "dependencies": {
     "app-root-path": "2.1.0",
     "frg-ethereum-runners": "https://github.com/ampleforth/frg-ethereum-runners.git#v1.0.0-alpha",
-    "js-yaml": "^3.13.0",
+    "js-yaml": "^3.13.1",
     "openzeppelin-eth": "2.0.2",
     "truffle": "4.1.14"
   },