'Verify getting columns by index'

def test_get_col(self):

    self.assertEqual(self.founders.get_col(list(self.headers).index('first_name')), [self.john[0], self.george[0], self.tom[0]])
    self.assertEqual(self.founders.get_col(list(self.headers).index('last_name')), [self.john[1], self.george[1], self.tom[1]])
    self.assertEqual(self.founders.get_col(list(self.headers).index('gpa')), [self.john[2], self.george[2], self.tom[2]])
