Feature/visibility

[jnation3406]

This adds endpoints for api/visibility/intervals and api/visibility/airmass to get visibility intervals or airmass values for targets at telescopes in a time range. It's using the rise_set library LCO maintains for visibility calculations since its faster and better suited to large queries then the other python options out there.

Right now it supports ICRS (ra/dec) targets or non-sidereal orbital elements based minor planets, major planets, or comets targets. It supports the constraints of airmass, lunar phase, and lunar angular separation distance. It can also be filtered by specific telescope. We will need to do more work once we get future planned telescope/instrument states to incorporate those outage times with the intervals returned.

[coveralls]

Pull Request Test Coverage Report for Build 14000611903

Details

• 526 of 531 (99.06%) changed or added relevant lines in 7 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+3.9%) to 89.041%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
heroic_api/views.py	27	28	96.43%
heroic_api/serializers.py	101	105	96.19%

Totals
Change from base Build 13923239888:	3.9%
Covered Lines:	1495
Relevant Lines:	1679

---

💛 - Coveralls

[baltierra]

Everything looked good to me, I'll merge.