Gammapy v0.15 release

[Axel Donath]

Dear Gammapy community,

after two months of intense coding we are happy to announce the release of Gammapy v0.15!

Gammapy v0.15 comes with many new features, such as an improved high level interface,

a unified and improved data reduction API and support for spatially varying energy dispersion

and point spread function. In addition we put a lot of effort into restructuring and improving

the existing documentation and tutorials.

A complete list of changes can be found here:

https://docs.gammapy.org/0.15/changelog.html#dec-3-2019

conda packages are already available for Python 3.6 and 3.7, Python 3.8 will follow soon. As usual

we also provide a dedicated conda environment file. Detailed instructions for the installation can be

found here:  

https://docs.gammapy.org/0.15/install/index.html

Please try out Gammapy v0.15 and give us feedback! Also let us know if you find any issues

or have questions of any kind, either on this mailing list, gammapy.slack.com, or via

https://github.com/gammapy/gammapy.

A big thanks to all contributors!

Axel, for the developer team