title: How can I get Travis-CI to recognize and open external files during testing
body: <p>The last few failing builds pass fine on my computer, but I am having trouble getting them to pass on travis.  The problem is coming from there few lines in the tests (and other similar operations): <a href="https://github.com/garth5689/pyd2l/blob/master/test/pyd2l_test.py#L15-L20" rel="nofollow">https://github.com/garth5689/pyd2l/blob/master/test/pyd2l_test.py#L15-L20</a></p>
  
  <p>In my tests, since I have complicated data to test against, I have pickled this data to easily open it back up again and not have to hit the website I'm scraping multiple times every time I test.  (Feel free to discuss the merits of this test strategy, but that's not the topic of the question.)</p>
  
  <pre><code>class PyD2LMethodsTest(unittest.TestCase):
  
      def setUp(self):
          with open('./soup_1899_pickle.pkl', 'rb') as soup_pickle: 
              self.soup = pickle.load(soup_pickle)
          with open('./soup_1899_details_pickle.pkl', 'rb') as details_pickle: 
              self.test_details = pickle.load(details_pickle)
          with open('./test_Match_1899_pickle.pkl', 'rb') as test_Match_pickle: 
              self.test_match = pickle.load(test_Match_pickle)
  </code></pre>
  
  <p>This results in the following series of errors in my travis build: </p>
  
  <pre><code>======================================================================
  ERROR: test_calculate_reward_rounded_ceil (pyd2l_test.MatchTest)
  ----------------------------------------------------------------------
  Traceback (most recent call last):
    File "/home/travis/build/garth5689/pyd2l/test/pyd2l_test.py", line 70, in setUp
      with open('./test_Match_1899_pickle.pkl', 'rb') as test_Match_pickle: self.test_= pickle.load(
  FileNotFoundError: [Errno 2] No such file or directory: './test_Match_1899_pickle.pkl'
  </code></pre>
  
  <p>Here is the directory structure</p>
  
  <pre><code>pyd2l (repo)
  |-- pyd2l
  |   |-- (actual source files) 
  |
  +-- test
      |-- pyd2l_test.py   
      |-- soup_1899_details_pickle.pkl
      |-- soup_1899_pickle.pkl
      |-- soup_404_pickle.pkl
      +-- test_Match_1899_pickle.pkl
  </code></pre>
  
  <p>The tests all run fine on my local machine.  (I added the <code>./</code> to the file name during my testing to see if I could get it to work on my own.  I think there might be something in the environment variables that I need to work with, but I'm not sure.  There might also be the possibility that travis doesn't allow pickling/unpickling, but I couldn't find anything to that effect.  Any help is appreciated.</p>
  
  <p>Travis builds: <a href="https://travis-ci.org/garth5689/pyd2l/builds" rel="nofollow">https://travis-ci.org/garth5689/pyd2l/builds</a></p>