Update module import path for changed @actions/[email protected] package structure

The module path usable with the 1.x series of the package caused build to fail:

src/installer.ts:8:23 - error TS2307: Cannot find module '@actions/http-client/auth' or its corresponding type declarations.

Author: per1234

src/installer.ts

@@ -5,7 +5,7 @@ import * as os from "os";
 import * as path from "path";
 import * as util from "util";
 import * as httpm from "@actions/http-client";
-import * as auth from "@actions/http-client/auth";
+import * as auth from "@actions/http-client/lib/auth";
 import * as semver from "semver";
 
 if (!tempDirectory) {