Allow push of any type of archive

I added some code to allow any type of archive to be pushed rather than just .zip/.war/.jar. To do this I check if the magic number "PK" is contained. 
If multiple apps are located in the path defined only the first found will be pushed.

Regarding the CLA agreement as an IBM employee I shouldn't need to sign it though. If necessary I can refer you to the person responsible for these things.

Also for the testing I believe the RSpec available already covers the bit I added.