Fetch tyesafe artifacts using https

See http://blog.ontoillogical.com/blog/2014/07/28/how-to-take-over-any-java-developer/

Seems some people are having problems with typesafe's ssl cert, so may want to fix that before comitting this. Sounds like [the solution](http://stackoverflow.com/questions/18746565/godaddy-ssl-cert-not-working-with-java/21117993#21117993) for Java not supporting GoDaddy G2 certs is for typesafe to rekey it's SSL cert using SHA-1
http://support.godaddy.com/help/article/4976/re-keying-an-ssl-certificate

Hopefully that's not too much trouble. If it ends up being tricky, could also just buy an SSL cert from someplace else. They start at $4.99/yr from ssls.com