feat: use small HTTP dependency (#510)

Improve load time from 1000 ms to under 800 ms.

Drive-by fix: Delete unused import.

package.json

@@ -57,6 +57,7 @@
     "once": "^1.4.0",
     "post-install-check": "0.0.1",
     "proxyquire": "^2.0.0",
+    "request": "^2.88.0",
     "require-inject": "^1.4.3",
     "rimraf": "^2.6.2",
     "source-map-support": "^0.5.6",
@@ -74,10 +75,10 @@
     "gcp-metadata": "^0.7.0",
     "lodash": "^4.12.0",
     "p-limit": "^2.0.0",
-    "request": "^2.81.0",
     "semver": "^5.5.0",
     "source-map": "^0.6.1",
     "split": "^1.0.0",
+    "teeny-request": "^3.6.0",
     "util.promisify": "^1.0.0"
   },
   "scripts": {

src/agent/controller.ts

@@ -21,7 +21,9 @@
 import {ServiceObject} from '@google-cloud/common';
 import * as assert from 'assert';
 import * as qs from 'querystring';
-import * as request from 'request';
+import * as request from 'request';  // Only for type declarations.
+import {teenyRequest} from 'teeny-request';
+
 import {URL} from 'url';
 
 import {Debug} from '../client/stackdriver/debug';
@@ -41,7 +43,11 @@ export class Controller extends ServiceObject {
    */
 
   constructor(debug: Debug, config?: {apiUrl?: string}) {
-    super({requestModule: request, parent: debug, baseUrl: '/controller'});
+    super({
+      requestModule: teenyRequest as typeof request,
+      parent: debug,
+      baseUrl: '/controller'
+    });
 
     /** @private {string} */
     this.nextWaitToken = null;

src/agent/debuglet.ts

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-import {GoogleAuthOptions} from '@google-cloud/common';
 import * as assert from 'assert';
 import * as consoleLogLevel from 'console-log-level';
 import * as crypto from 'crypto';

src/client/stackdriver/debug.ts

@@ -15,7 +15,8 @@
  */
 
 import {GoogleAuthOptions, Service} from '@google-cloud/common';
-import * as request from 'request';
+import * as request from 'request';  //  Only for type declarations.
+import {teenyRequest} from 'teeny-request';
 
 export interface PackageInfo {
   name: string;
@@ -57,7 +58,7 @@ export class Debug extends Service {
     }
 
     const config = {
-      requestModule: request,
+      requestModule: teenyRequest as typeof request,
       projectIdRequired: false,
       baseUrl: 'https://clouddebugger.googleapis.com/v2',
       scopes: ['https://www.googleapis.com/auth/cloud_debugger'],