Configurable storage path

As per #77, this PR adds --storage-path/MACHINE_STORAGE_PATH (env var)
to allow the user to specify where they want to store the machine db

Signed-off-by: Simon Thulbourn <simon+github@thulbourn.com>
Merge pull request #131 from sthulb/configure-path

Configurable storage path
started on integration tests

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>
allow filtering driver integration tests

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>
added helper script for running tests in docker

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>
update travis to skip integration tests

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>
fix test script

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>
added test docs to readme; add doc info to tests

Signed-off-by: Evan Hazlett <ejhazlett@gmail.com>