* improve derivation-checking performance by batching docker calls; move into spec dir
* remove npm command to run derivation-checking; create 'int-test' (integration) command and hook up into jest
* add integration testing to CI; configure docker / docker image (dternyak/eth-priv-to-addr) in CI
* docker build -> docker pull
* use travis build matrix to group tests and improve build times
* remove int-test call
* attempt travis 'job' with all tests running in parallel
* remove typo
* attempt travis 'job' with all tests running in parallel (round 2)
* organize integration tests
* refactor/cleanup
* refactor/address comments
Daniel Ternyak