Update pom to version 0.4.

Author: ebarlas

pom.xml

@@ -9,7 +9,7 @@
     <name>Micro HTTP Server</name>
     <description>Microhttp is an event-driven, single-threaded, zero-dependency web server</description>
     <url>https://github.com/ebarlas/microhttp</url>
-    <version>0.4-SNAPSHOT</version>
+    <version>0.4</version>
 
     <licenses>
         <license>