Add a GNU AGPLv3 license file
Add a GNU AGPLv3 license file

Thereby licensing everything under the GNU Affero General Public License
version 3. We should consider adding license headers to every new file
added after this commit. In addition to that we actually need to ensure
that all licenses in our dependency tree are GPL compatible (no
exceptions).

See also: https://www.gnu.org/licenses/agpl#howto

stefanoberdoerfer/exmatrikulator,stefanoberdoerfer/exmatrikulator,stefanoberdoerfer/exmatrikulator,stefanoberdoerfer/exmatrikulator,stefanoberdoerfer/exmatrikulator