Create a script for travis that tests all the bnsapi endpoints

[annatorok]

Goal: it would be vital to filter out any breaks when changes are made to bnsapi.

eg.
the endpoints /escrow/escrows and /multsig/contracts both return empty arrays when queried against mainnet. They definitely should not be empty

[orkunkl]

I've finished the integration testing script and writing tests for handlers. Some of the handlers(escrows, multisig) is not working and I am fixing them as I proceed with testing. This issue will take some time.