extractFiles fix main in package.json

Author: Jason Sholl

Tasks/ExtractFiles/package.json

@@ -2,7 +2,7 @@
   "name": "extractFiles",
   "version": "1.0.0",
   "description": "Extract Files Task",
-  "main": "extractFiles.js",
+  "main": "extractfilestask.js",
   "repository": {
     "type": "git",
     "url": "git+https://github.com/Microsoft/vsts-tasks.git"