The exit code is always 0 regardless if there are failures or not

[khaledhosny]

Observed behaviour

The exist code is always zero, regardless if there are failing checks or if -e is used.

Expected behaviour

There error code should be non-zero if there failing checks (or the level set with -e)

[khaledhosny]

This appears to happen only when called as python -m fontbakery, should be fixed with #4634.

[felipesanches]

thanks!