Exotethys

* Added Stagger_2018 stellar models grid, which extends the wavelength coverage of Stagger_2015 up to 20 micron (everything else is identical in the common wavelength range).

* Added option to interpolate stellar spectra from the available grids in boats.get_model_spectrum

* Increased default resolution from 1e4 to 1e6 for get_waves_fromR (both in SAIL and BOATS)
* Fixed read_wavelength_bins using os.path.join
* Fixed bugs in sail.get_intensities_from_ldcs with gen_claret and gen_poly laws.

Second online release
* Added BOATS and manage_database subpackages
* Added Phoenix_drift_2012 and Stagger_2015 stellar models grids in the online database
* Using quantity arrays with astropy.units instead of numpy arrays in the files of the stellar model grids
* Including disk-integrated stellar spectra in addition to the specific intensities in the files of the stellar model grids
* Added new precalculated passbands
* Slightly revised algorithms for the SAIL subpackage, but results are unaffected
* Reduced default number of annuli for the TRIP calculation, after testing precision
* Provided detailed user manuals for each subpackage and a revised README.adoc
* Added FAQ section in the wiki
* Added new examples and auxiliary files
* New organization of the GitHub repository

Version fully revised by the JOSS reviewers
* Added documentation with docstrings
* Added ``pytest`` tests and [Travis](https://docs.travis-ci.com/) continuous integration
* Fixed small issues and bugs
* Added history and community guidelines files
* Made repository pip-installable

Version under revision by the [Journal of Open Source Software (JOSS)](https://joss.theoj.org/)
* Added new database Atlas\_2000
* Phoenix\_2012\_13 and Phoenix\_2018 databases migrated to a different online directory
* Added check to passband wavelength limits
* Added error message if all required targets cannot be calculated