Bump parent version to 38-SNAPSHOT

Why:
- Prepare for the next development iteration with updated parent version.

Author: slawekjaranowski

pom.xml

@@ -24,7 +24,7 @@ under the License.
   <parent>
     <groupId>org.apache</groupId>
     <artifactId>apache</artifactId>
-    <version>37</version>
+    <version>38-SNAPSHOT</version>
     <relativePath />
   </parent>