Unit Test upgrade and bugfix for unformatted files

[jklenzing]

Description

Addresses #62.

• Additional unit tests
  • Now checks for runs and loads with both the formatted and unformatted output options
  • Basic check for Model.repr()
  • Added tests for input of fourier series for ExB drifts
  • Separated test archive data for unformatted and formatted data to different days.
  • Updated test code to use os.path.join to improve platform independence.
  • Removed test codes from coverage report
• Bugfix for unformatted data load
• Bugfix for check for standard data as part of repr
• Update to pull request template
• PEP8 scrub

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• Make sure you are merging into the develop (not master) branch
• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules