Make tests runnable with pytest.

Also update travisci to use pytest.

.travis.yml

@@ -14,6 +14,7 @@ install:
 script:
 - echo -e 'x=0\nfor i in range(0, 10000000):\n    x+=i\nprint(x)' > fake.py
 - howlong -i 1 -c python fake.py
+- pytest
 
 after_success:
 - bash <(curl -s https://codecov.io/bash)

HowLong/test_parser.py

@@ -1,6 +1,5 @@
 import unittest
-from HowLong import HowLong
-
+from HowLong.HowLong import HowLong
 
 class TestParser(unittest.TestCase):
 
@@ -13,7 +12,7 @@ def test_empty_arguments(self):
         '''Tests with no arguments
             At least one argument is required.
         '''
-        with self.assertRaises(AssertionError):
+        with self.assertRaises(SystemExit):
             self.parser()
 
     def test_c_option_with_empty_arguments(self):
@@ -29,7 +28,3 @@ def test_p_option_with_empty_arguments(self):
         '''
         with self.assertRaises(TypeError):
             self.parser('-p')
-
-
-if __name__ == "__main__":
-    unittest.main()

requirements.txt

@@ -1,4 +1,7 @@
 psutil>=5.0.1
 termcolor>=1.1.0
 colorama>=0.3.9
+pytest==3.9.2
+pytest-cov==2.6.0
+six==1.11.0
 -e .