Add snapcraft yaml

[LyzardKing]

This PR adds a snap yaml file that generates the snap package.
It's been briefly tested on my system, but might need more testing.

[DamirPorobic]

Awesome, thanks for providing this PR. This can be used to locally build the snap? The snap needs then to be pushed manually to snapcraft, right?

[LyzardKing]

This can be used to build locally,
but you can create an account on build.snapcraft.io, link it to your github and add the ksnip repo.
Then It'll automatically build on every commit to master.

[DamirPorobic]

Is it possible to differentiate between tagged and untagged build? Tagged build are finished releases.

Anyways, thanks for providing this, I'll test the build take care of the integration with snapcraft.

[DamirPorobic]

Implements #147

[LyzardKing]

If you add it on build.snapcraft.io it'll upload the builds from master to the "-edge" channel.
Then you can manually set that to "-stable" when you make a proper release.

[DamirPorobic]

Awesome, thanks for clarifying :)

[DamirPorobic]

@LyzardKing I had finally time to build the snap locally and via build.snapcraft.io though with both I get following error:
/snap/ksnip/x1/bin/ksnip: error while loading shared libraries: libQt5Network.so.5: cannot open shared object file: No such file or directory

I can't see any Qt dependencies that you have defined in the yaml, where do I need to set it?

Also, just for your information, I was able to build the snap with the yaml that you have provided but uploading to snapcraft.io failed with a strange messages. After some investigation I figured out that the description section in the yaml was missing, which seems to be mandatory, after adding it, I was able to upload it.

[LyzardKing]

You're right.. I completely forgot to mention this!
Since I added the kde content snap to be able to run ksnip you first need to run:
snap connect ksnip:kde-frameworks-5-plug kde-frameworks-5-core18:kde-frameworks-5-core18-slot

Regarding the description, I had omitted it thinking it would be read form the appdata xml

[LyzardKing]

@DamirPorobic You can then ask for it to be autoconnected on the snapcraft forum!

[DamirPorobic]

@LyzardKing thanks again for your feedback here, it's very helpful. Regarding the description, you're probably right, after I wrote the post above I've noticed a message telling me that there is a description in the xml will be overwritten by the one from the yaml. Probably the one from the xml has a wrong format, it has htmls tags. Will investigate that later on.

Regarding the autoconnect, can I ask right away to be autoconnected or does something need to happen before we get that autoconnect?

[DamirPorobic]

I need to open a topic here https://forum.snapcraft.io/c/store-requests and ask to connect ksnip to kde-frameworks-5-core18, right?