Use UTF-8 as default project encoding

pom.xml

@@ -11,8 +11,12 @@
 
     <properties>
         <java.version>11</java.version>
-        <maven.compiler.source>11</maven.compiler.source>
-        <maven.compiler.target>11</maven.compiler.target>
+        <maven.compiler.source>${java.version}</maven.compiler.source>
+        <maven.compiler.target>${java.version}</maven.compiler.target>
+
+        <encoding>UTF-8</encoding>
+        <project.build.sourceEncoding>${encoding}</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>${encoding}</project.reporting.outputEncoding>
 
         <!-- 3rd party dependencies -->
         <nimbus.version>9.19</nimbus.version>
@@ -34,7 +38,6 @@
         <maven-surefire-plugin.version>3.0.0-M7</maven-surefire-plugin.version>
         <maven-failsafe-plugin.version>3.0.0-M7</maven-failsafe-plugin.version>
         <maven-checkstyle-plugin.version>3.1.2</maven-checkstyle-plugin.version>
-
     </properties>
 
     <modules>