chore(deps): update dependency mocha to v7

Author: renovate-bot

package.json

@@ -116,14 +116,14 @@
     "@sourcegraph/eslint-config": "^0.12.0",
     "@sourcegraph/prettierrc": "^3.0.3",
     "@sourcegraph/tsconfig": "^3.0.0",
-    "@types/mocha": "5.2.7",
+    "@types/mocha": "7.0.2",
     "@types/node": "12.7.3",
     "@types/sinon": "7.0.13",
     "eslint": "^6.8.0",
     "husky": "^1.3.1",
     "lnfs-cli": "^2.1.0",
     "mkdirp": "^1.0.3",
-    "mocha": "^6.0.2",
+    "mocha": "^7.1.1",
     "nyc": "^13.3.0",
     "parcel-bundler": "^1.11.0",
     "prettier": "^1.16.4",