Bump snap version to 3.1.0

snap/snapcraft.yaml

@@ -1,6 +1,6 @@
 name: czkawka # you probably want to 'snapcraft register <name>'
 base: core18 # the base snap is the execution environment for this snap
-version: '3.0.0' # just for humans, typically '1.2+git' or '1.3.2'
+version: '3.1.0' # just for humans, typically '1.2+git' or '1.3.2'
 summary: Czkawka - fast data cleaner written in Rust # 79 char long summary
 description: |
   Czkawka is very fast and feature rich cleaner which finds file duplicates, empty folders and files, duplicated music, similar images or the biggest files in selected directories.
@@ -33,4 +33,4 @@ apps:
     plugs:
       - home
       - removable-media
-      - udisks2
+      - udisks2