* Build and CI improvements
In this commit we:
1) Parallelize the Travis CI config, by splitting
each project into its own Travis task
2) Download bitcoind binaries through sbt
* Use binaries downloaded by sbt task
* Make BitcoindRpcTestUtil work on Travis without bitcoind on PATH
* Add new downloadEclair task to sbt
* use sbt downloaded binaries in tests
* Fix Eclair and Bitcoind tests