Conda packaging

• Updated to work with Python 3
• Added unit tests to ensure basic functionality of data2passcal
• Updated list of platform specific dependencies to be installed when installing data2passcal in dev mode (see setup.py)
• Installed and tested data2passcal against Python 2.7 and Python 3.[5,6,7,8] using tox
• Formatted Python code to conform to the PEP8 style guide
• Created conda package for data2passcal that can run on Python 2.7 and Python 3.[5,6,7,8]
• Updated .gitlab-ci.yml to run a linter and unit tests for Python 2.7 and Python 3.[5,6,7,8] in GitLab CI pipeline

conda.recipe/meta.yaml

@@ -24,7 +24,6 @@ test:
   source_files:
     - tests
   commands:
-    - python -c "import data2passcal.data2passcal; print(data2passcal.__version__)"
     - python -m unittest tests.test_data2passcal
 
 about: