chore(deps): update dependency mocha to v7 (#420)

Author: renovate-bot

packages/google-cloud-translate/package.json

@@ -73,7 +73,7 @@
     "jsdoc-fresh": "^1.0.1",
     "jsdoc-region-tag": "^1.0.2",
     "linkinator": "^1.5.0",
-    "mocha": "^6.1.4",
+    "mocha": "^7.0.0",
     "pack-n-play": "^1.0.0-2",
     "power-assert": "^1.6.0",
     "prettier": "^1.13.5",

packages/google-cloud-translate/samples/package.json

@@ -23,7 +23,7 @@
   "devDependencies": {
     "@google-cloud/storage": "^4.0.0",
     "chai": "^4.2.0",
-    "mocha": "^6.0.0",
+    "mocha": "^7.0.0",
     "uuid": "^3.3.2"
   }
 }