ADD: Adding ameriflux discovery module. This module is based on the R code amerifluxr

[zssherman]

• Tests added
• Documentation reflects changes
• PEP8 Standards or use of linter
• Xarray Dataset or DataArray variable naming follows 'ds' or 'da' naming

[zssherman]

Note, I still need to add tests and examples

[zssherman]

@AdamTheisen Should we leave the default to agree_policy False? So users read the policy first? I was debating how to approach that...

[AdamTheisen]

@zssherman I didn't get a chance to review today but blocking my calendar Wed afternoon

[zssherman]

@AdamTheisen no worries!

[zssherman]

@AdamTheisen I did changes to address your comments. Let me know if the recent commit looks good for all your comments. For the is test I add a kwargs, but once we have the seceret email and username added, ill add one more check to the is test. That way we keep that hidden, but still available for our unit tests

[zssherman]

@AdamTheisen Added the new reader, ready for review when folks have time. Working on the tests still though

[AdamTheisen]

@zssherman I cc'd you in on the email from the AmeriFlux developers and I think you hit all their requirements. I think this is looking good as well once we get the tests working!