[#484] Bump release number for new tezos-baking package

Problem: we've updated the tezos-baking package and would like to
release the changes in a new version, for which we need to bump the
release number.

Solution: bumped the release number and updated the letter version
of tezos-baking.

docker/package/model.py

@@ -494,7 +494,7 @@ class TezosBakingServicesPackage(AbstractPackage):
     # native releases, so we append an extra letter to the version of
     # the package.
     # This should be reset to "" whenever the native version is bumped.
-    letter_version = "a"
+    letter_version = "b"
 
     buildfile = "setup.py"
 

meta.json

@@ -1,4 +1,4 @@
 {
-    "release": "2",
+    "release": "3",
     "maintainer": "Serokell <[email protected]>"
 }