Run UT as root inside the container
Run UT as root inside the container

The code coverage module requires the /code directory to be
writable, which it won't be if the UID of the user outside the container
doesn't match the UID of the `user` user inside the container.

Running under `user` is only required for pyinstaller, not UTs.


Former-commit-id: 8c892c3e3845150d1ddc0241c4f85e5baaf6a908
TrimBiggs/libcalico,alexhersh/libcalico,TrimBiggs/libnetwork-plugin,plwhite/libcalico,Symmetric/libcalico,TrimBiggs/libnetwork-plugin,djosborne/libcalico,robbrockbank/libcalico,tomdee/libcalico,caseydavenport/libcalico,projectcalico/libcalico,projectcalico/libnetwork-plugin,tomdee/libnetwork-plugin,insequent/libcalico,L-MA/libcalico