ENH: Unit test for import with bad fortran compilation

[aburrell]

Is your feature request related to a problem? Please describe.
The only coverage that is missing is for the warnings raised when apexpy is not correctly installed due to a failed attempt at compiling the fortran code.

Describe the solution you'd like
A unit test for this occurance.

Describe alternatives you've considered

# -*- coding: utf-8 -*-
"""Test the apexpy initial import
"""

from glob import glob
import os
import sys
import warnings


class TestFortranInit():
    def setup(self):
        """Initialize each test."""
        from apexpy import helpers  # NOQA 401

        # Get the original file
        self.orig_file = glob(os.path.join(
            os.path.dirname(sys.modules['apexpy.helpers'].__file__),
            'fortranapex*{:d}{:d}*'.format(sys.version_info.major,
                                           sys.version_info.minor)))[0]
        del sys.modules['apexpy.helpers'], helpers

        # Move the original file
        self.temp_file = "temp_lib"
        os.rename(self.orig_file, self.temp_file)
        return

    def teardown(self):
        """Clean environment after each test."""
        os.rename(self.temp_file, self.orig_file)
        del self.temp_file, self.orig_file
        return

    def test_bad_fortran_location(self, capsys):
        """Test the warnings and errors when fortran library is missing."""
        # Test the bad import
        with warnings.catch_warnings(record=True) as warn_rec:
            import apexpy  # NOQA 401
            captured = capsys.readouterr()

        # Test the warning message
        assert len(warn_rec) == 1
        assert str(warn_rec[0].message).find("fortranapex module could ") >= 0

        # Test the stderr output
        assert captured.err.find("apexpy probably won't work") >= 0

        return

Additional context
The above test doesn't work.

Reminders
This is a volunteer-driven project. Code contributions are welcome, as is help
testing new code.