Use Azure storage SDK to download cache (#497)

* Adds option to download using AzCopy

* Bump version number and add release notes

* Ensure we use at least v10

* Negate env var so it disables AzCopy

* Use Azure storage SDK to download cache

* Use same level of parallelism as AzCopy

* Fix naming of variable

* React to feedback

* Bump Node types to Node 12

* Make linter happy

* Pass options into restoreCache method

* Fix tests

* Restructure files and add tests

* Add method to get the default download and upload options

* Include breaking changes in RELEASES.md

Co-authored-by: Josh Gross <joshmgross@github.com>

package.json

@@ -14,7 +14,7 @@
   },
   "devDependencies": {
     "@types/jest": "^24.0.11",
-    "@types/node": "^11.13.5",
+    "@types/node": "^12.12.47",
     "@types/signale": "^1.2.1",
     "@typescript-eslint/parser": "^2.2.7",
     "concurrently": "^4.1.0",