Prepare 0.5.5.0 release

[ci skip]

Changelog.md

+# 0.5.5.0
+
+## Refactor
+
+## Bug fixes
+
+## Features
+
 # 0.5.4.0
 
 ## Refactor

config/defaults.yml

@@ -4,7 +4,7 @@
 
 defaults:
   version:
-    number: "0.5.3.99" # Do not touch unless doing a release, do not backport the version number that's in master
+    number: "0.5.4.99" # Do not touch unless doing a release, do not backport the version number that's in master
   heroku: false
   environment:
     url: "http://localhost:3000/"