Adjusted container file will provide pytest framework out of the box
to facilitate testing code from VS code IDE.
Package installation layers were consolidated in order to minimize
image size.
Default devcontainer configuration was added.
Signed-off-by: Jiri Podivin <jpodivin@redhat.com>
Change-Id: Id9fb1bf52bdf4c9d0bad09cd9604c4a4114c5b62