chore(package): update @types/mocha to version 7.0.2

Closes #39

Author: greenkeeper[bot]

package.json

@@ -78,7 +78,7 @@
     "test": "npm run compile && node ./node_modules/copy/bin/cli.js \"src/test/testdata/**\" \"out/test/testdata\" && node ./node_modules/vscode/bin/test"
   },
   "devDependencies": {
-    "@types/mocha": "^5.2.4",
+    "@types/mocha": "^7.0.2",
     "@types/node": "^10.5.2",
     "copy": "^0.3.1",
     "typescript": "^2.6.1",