Require package names not to contain uppercase letters nor underscores

Author: findepi

CHANGES.md

@@ -1,5 +1,6 @@
 Airbase 91
 
+* Require package names not to contain uppercase letters nor underscores.
 * Dependency updates:
   - Jackson 2.9.8 (from 2.9.7)
 * Plugin updates:

airbase-policy/src/main/resources/checkstyle/airbase-checks.xml

@@ -159,7 +159,9 @@
         <module name="LocalVariableName" />
         <module name="LocalFinalVariableName" />
         <module name="TypeName" />
-        <module name="PackageName" />
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$" />
+        </module>
         <module name="ParameterName" />
         <module name="StaticVariableName" />
         <module name="ClassTypeParameterName">