Standardize code to F2008

[ewu63]

Purpose

I had to use F2003 because certain features were relying on it. Code can also be compiled on GCC 10 now.

Type of change

What types of change is it?
Select the appropriate type(s) that describe this PR

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Tests pass with the new -std flag.

Checklist

Put an x in the boxes that apply.

• I have run flake8 and black to make sure the code adheres to PEP-8 and is consistently formatted
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[ewu63]

Also this

[akleb]

The comma makes sense to me, but are the parentheses required? I am not sure what they are doing.

[ewu63]

I am not familiar with file IO specifications, not really sure :/ maybe @anily knows?

[akleb]

If we are planning on eventually updating to 2008 on all our codes, then would it makes sense to just knock that out here? I suspect it may already be 2008 compliant, or at least very close.

[marcomangano]

If the tests are working and the update is complete, I am fine with merging this. I am just changing the PR title to avoid confusion

[akleb]

I think this is all fine, looks the same as what I had for my corrections to pyHyp. As for the parentheses question I think they just signify groupings, which in this case doesn't matter so it should be fine with or without them.