Secondarycoolantprops

What's Changed
* Update Tests by mitchute in https://github.com/mitchute/SecondaryCoolantProps/pull/14
* Update README by mitchute in https://github.com/mitchute/SecondaryCoolantProps/pull/13
* Update RTD by mitchute in https://github.com/mitchute/SecondaryCoolantProps/pull/15


**Full Changelog**: https://github.com/mitchute/SecondaryCoolantProps/compare/v1.1...v1.2

Updates freeze point calcs.

Release as v1.0. Contains property calculation routines for water and for aqueous mixtures of propylene glycol, ethylene glycol, ethanol, and methanol.

Ultra simple version that returns constant values for PG and EG.

test_02
This will be deleted.

test_01
Testing. This will be deleted.