Update pylintrc

Since the current pylintrc is in now way good for our style, we update
it:

- remove docstring checks, since we have too many cases where a
  docstring doesn't make sense
- relax naming rules to cover more alternatives (but not break the
  naming rules)
- increase many of the limits

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Olivier Tharan <olive@google.com>