chore(deps-dev): bump cross-env from 6.0.3 to 7.0.0 (#31)

Bumps [cross-env](https://github.com/kentcdodds/cross-env) from 6.0.3 to 7.0.0.
- [Release notes](https://github.com/kentcdodds/cross-env/releases)
- [Changelog](https://github.com/kentcdodds/cross-env/blob/master/CHANGELOG.md)
- [Commits](kentcdodds/cross-env@v6.0.3...v7.0.0)

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

package.json

@@ -37,7 +37,7 @@
     "chai": "^4.2.0",
     "chai-bytes": "~0.1.2",
     "chai-checkmark": "^1.0.1",
-    "cross-env": "^6.0.3",
+    "cross-env": "^7.0.0",
     "dirty-chai": "^2.0.1",
     "go-libp2p-dep": "~0.5.0",
     "libp2p-daemon": "^0.3.0",