Updates to @actions/artifact (#396)

* Add support for 429s and Exponential backoff

* Refactor status-reporter so it can be used with download and upload

* Extra logs

* Fixes around download & gzip

* Cleanup headers and add extra tests

* Improved Docs

* Spelling bloopers

* Improved error messages

* User http client version 1.0.7

package.json

@@ -37,7 +37,7 @@
   },
   "dependencies": {
     "@actions/core": "^1.2.1",
-    "@actions/http-client": "^1.0.6",
+    "@actions/http-client": "^1.0.7",
     "@types/tmp": "^0.1.0",
     "tmp": "^0.1.0",
     "tmp-promise": "^2.0.2"