Added reference to paper for OAS integration work

[eytanadler]

Purpose

Added a short note on the new OAS work with a bibtex citation to the paper and updated other outdated information on the readme.

Type of change

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

• Documentation update

Testing

Explain the steps needed to test the new code to verify that it does indeed address the issue and produce the expected behavior.

Checklist

Put an x in the boxes that apply.

• [ ] 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

[coveralls]

Pull Request Test Coverage Report for Build 1740968238

• 2 of 3 (66.67%) changed or added relevant lines in 2 files are covered.
• 22 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.4%) to 87.428%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
openconcept/analysis/openaerostruct/drag_polar.py	1	2	50.0%
<!--	Total:	2	3	66.67%	-->

Files with Coverage Reduction	New Missed Lines	%
openconcept/analysis/openaerostruct/drag_polar.py	22	92.2%
<!--	Total:	22		-->

Totals
Change from base Build 1730143752:	-0.4%
Covered Lines:	5306
Relevant Lines:	6069

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💛 - Coveralls

[eytanadler]

Ah ok I'll add it back then. Before this is merged, I'm also going to see if I can figure out some of the warnings in the tests.