Add prototype action using exec and curl

* Downloads a fixed version Julia binary using curl
* Adds it to PATH
* Runs `julia --version` to test the installation

lib/file.js

@@ -0,0 +1,3 @@
+"use strict";
+// Apparently this satisfies the typescript compiler
+// https://stackoverflow.com/questions/41211566/tsconfig-json-buildno-inputs-were-found-in-config-file/45790421#45790421