Make filter regex more inclusive

so that it filters out more `"no previously-included..."` warnings from distutils while installing.

##### Before:

    $ pip install -e ~/dev/git-repos/pip
    Obtaining file:///Users/marca/dev/git-repos/pip
        warning: no previously-included files found matching '.coveragerc'
        warning: no previously-included files found matching '.mailmap'
        warning: no previously-included files found matching '.travis.yml'
        warning: no previously-included files found matching 'pip/_vendor/Makefile'
        warning: no previously-included files found matching 'tox.ini'
        no previously-included directories found matching '.travis'
        no previously-included directories found matching 'docs/_build'
        no previously-included directories found matching 'contrib'
        no previously-included directories found matching 'tasks'
        no previously-included directories found matching 'tests'
    Installing collected packages: pip
      Running setup.py develop for pip
        warning: no previously-included files found matching '.coveragerc'
        warning: no previously-included files found matching '.mailmap'
        warning: no previously-included files found matching '.travis.yml'
        warning: no previously-included files found matching 'pip/_vendor/Makefile'
        warning: no previously-included files found matching 'tox.ini'
        no previously-included directories found matching '.travis'
        no previously-included directories found matching 'docs/_build'
        no previously-included directories found matching 'contrib'
        no previously-included directories found matching 'tasks'
        no previously-included directories found matching 'tests'
    ...

##### After:

    $ pip install -e ~/dev/git-repos/pip
    Obtaining file:///Users/marca/dev/git-repos/pip
    Installing collected packages: pip
      Running setup.py develop for pip
    ...