Experimental

See merge request !2

The following main changes to the code were made:
1. 2.8 API introduces new way of class registration. Instead of module registration now one has to register classes directly. See [1] for details.
2. Class property registration has also changed. Again, see [1] for details.
3. The redisigned interfaces has some window' names changed. For instance, INFO_MT_file_import has became TOPBAR_MT_file_import. See the following link for details [2]
4. bpy.context.user_preferences -> bpy.context.preferences
5. bpy.ops.wm.addon_enable -> bpy.ops.preferences.addon_enable
6. bpy.context.scene.objects.active = obj now became bpy.context.view_layer.objects.active = obj
7. obj.select = True now became obj.select_set(state = True)
Some additional minor changes to the code were implemented.

R E F E R E N C E S
1. https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Python_API/Addons
2. https://google.com