Don't clutter PATH with bash initialisation

[muellerj]

Passing -l to bash enables all path manipulations from the bash
initialisation chain (/etc/profile, /etc/bashrc, ~/.bash_profile,
~/.bash_login, ~/.profile, ~/.bashrc, etc.) to bleed through to
the fish shell. In order to avoid that, we should simply execute
chruby.sh without their influence.

[muellerj]

The CI error is not related to my change, I think.

[JeanMertz]

Thanks for the contribution!

This was changed at some point, but I can't remember why I did that (I was terrible at Git and documenting things back then 🙈).

This would be a breaking change, but I agree that this would be a better solution.

We'll still want to get the CI working again though, to make sure nothing else breaks. I don't have a lot of time right now to fix this, so if you can find some time, I'd appreciate that. If not, I'll keep this open until someone can spend some time on fixing the CI, or I find some time myself.

[muellerj]

My apologies for not responding sooner.

There seem to be two separate problems:

1. brew install fish --HEAD seems to fail on the CI without ever getting to the tests
2. When installing brew install fish, the tests get run and there is one failing test, which actually tests for .bash_profile support:

# test/chruby_test.fish:53
test "$TESTNAME: chruby supports .bash_profile"
  "$HOME" = (touch $HOME/tmp; chruby "2.2"; cat $HOME/tmp)
end

I don't quite understand how the test works. Also, evaluating (and thus allowing it to modify $PATH) .bash_profile seems to be a feature, since there are tests for it?

I would argue that with my proposed change, we should test that ~/.bash_profile is ignored. Since I don't understand how the test works, I don't feel confident modifying the tests. Can you give me a hint how (touch $HOME/tmp; chruby "2.2"; cat $HOME/tmp) prints the value of $HOME if chruby sources ~/.bash_profile?