We want to access the clientset (or at least check the fact that we're
in a cluster) outside of the Mirko object lifecycle.
In reality, this should _probably_ be moved outside of the Mirko library
and get a better API than this (ie. one that returns complete
information about the state of being in production/dev/...).
Change-Id: I86444477e0306a39a1611207855127a7b963603e
This uses github.com/golang-migrate/migrate and adds a Source that
allows using go_embed data files.
We also provide a test/example.
Change-Id: Icd2b6c7f7d0f728073b3fdf39b432b33ce61a3cd