Copr update and new API

[Valentin Gologuzov]

New version of Copr with preview of the new REST-like API.

Hi,  I am very glad to announce another Copr upgrade!

We have some major features:

* Added support for the comps.xml [1]. It allows you to provides
installation groups in your Copr repository.
Comps can  be uploaded in:
[details of your project] -> Edit -> Click on Edit beside selected 
chroot -> Upload comps.xml
It will be automatically added to package repository next time you build 
a package.
* If dist-git fails to import srpm, Copr now provides feedback with
failure description.
* Resubmit build is refactored, now it uses dist-git as a build source.
* Builds which failed during the import stage are now deletable.
* Lots of fixes and improvements in the frontend UI.

Last, but not least change, is a new API.
We aimed to provide a simple and well structured API which
covers as much Web UI functionality as possible.

Feel free to discover it [2] and read documentation [3].
This new API is not fixed yet,
we want to get your feedback and we may change it in future.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1237246
[2] https://copr.fedoraproject.org/api_2
[3] http://copr-rest-api.readthedocs.org/en/latest/