Adds a new bundle `verify-integration-tests` which pre-compiles a test
binary for the integration tests.
This makes sure that the integration tests will actually compile before
doing other tasks which take much longer, such as building dockerd and
loading test fixtures.
When it comes time to actually run the tests, the pre-compiled binary
will be used so it doesn't have to compile the tests a 2nd time.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
