Revert "Changed snap confinement to classic" (#278)

Classic mode is not allowed.

This reverts commit 00996ea.

Author: agnivade

snapcraft.yaml

@@ -5,7 +5,7 @@ description: |
   Node.js command line client for TLDR-pages
 
 grade: stable
-confinement: classic
+confinement: strict
 
 apps:
   tldr: