Remove support for Helm v2

[marckhouzam]

With Helm v2 having reached EOL, I was wondering if we should remove v2 support from the acceptance-tests.
The idea is simply to simplify the maintenance of the acceptance-tests.

Any opinion @jdolitsky?
I can handle the coding, if you agree with the idea.

[jdolitsky]

@marckhouzam - I have no problem with this