fix: bump min version of dependencies (#589)

packages/google-cloud-dialogflow/package.json

@@ -43,27 +43,26 @@
   },
   "dependencies": {
     "google-gax": "^2.1.0",
-    "protobufjs": "^6.8.0"
+    "protobufjs": "^6.8.9"
   },
   "devDependencies": {
-    "@types/mocha": "^5.2.5",
-    "@types/node": "^12.0.0",
+    "@types/mocha": "^7.0.2",
+    "@types/node": "^13.11.1",
     "@types/sinon": "^9.0.0",
-    "c8": "^7.0.0",
-    "codecov": "^3.0.0",
+    "c8": "^7.1.0",
+    "codecov": "^3.6.5",
     "gts": "^2.0.0",
-    "jsdoc": "^3.6.3",
-    "jsdoc-fresh": "^1.0.1",
-    "jsdoc-region-tag": "^1.0.2",
-    "linkinator": "^2.0.3",
-    "mocha": "^6.1.4",
+    "jsdoc": "^3.6.4",
+    "jsdoc-fresh": "^1.0.2",
+    "jsdoc-region-tag": "^1.0.4",
+    "linkinator": "^2.0.6",
+    "mocha": "^7.1.1",
     "null-loader": "^3.0.0",
     "pack-n-play": "^1.0.0-2",
-    "prettier": "^1.11.1",
-    "sinon": "^9.0.1",
-    "ts-loader": "^6.2.1",
+    "sinon": "^9.0.2",
+    "ts-loader": "^6.2.2",
     "typescript": "^3.8.3",
-    "webpack": "^4.41.2",
-    "webpack-cli": "^3.3.10"
+    "webpack": "^4.42.1",
+    "webpack-cli": "^3.3.11"
   }
 }

packages/google-cloud-dialogflow/system-test/install.ts

@@ -21,7 +21,7 @@ import {readFileSync} from 'fs';
 import {describe, it} from 'mocha';
 
 describe('typescript consumer tests', () => {
-  it('should have correct type signature for typescript users', async function() {
+  it('should have correct type signature for typescript users', async function () {
     this.timeout(300000);
     const options = {
       packageDir: process.cwd(), // path to your module.
@@ -35,7 +35,7 @@ describe('typescript consumer tests', () => {
     await packNTest(options); // will throw upon error.
   });
 
-  it('should have correct type signature for javascript users', async function() {
+  it('should have correct type signature for javascript users', async function () {
     this.timeout(300000);
     const options = {
       packageDir: process.cwd(), // path to your module.

packages/google-cloud-dialogflow/tsconfig.json

@@ -5,7 +5,7 @@
     "outDir": "build",
     "resolveJsonModule": true,
     "lib": [
-      "es2016",
+      "es2018",
       "dom"
     ]
   },