Increment minor version number

API.md

@@ -1,4 +1,4 @@
-API documentation for the HUD bars mod 0.3.0
+API documentation for the HUD bars mod 0.4.0
 ============================================
 
 **Warning**: This API is still experimental, everything may change at any time,

README.txt

@@ -1,6 +1,6 @@
 Minetest mod: HUD bars
 ======================
-Version: 0.3.0
+Version: 0.4.0
 
 This software uses semantic versioning, as defined by version 2.0.0 of the SemVer
 standard. <http://semver.org/>