PROTON-1387: use the standard properties to control compiler source/target version
diff --git a/pom.xml b/pom.xml
index 3ecf3bc..d8b3dec 100644
--- a/pom.xml
+++ b/pom.xml
@@ -30,6 +30,9 @@
   <packaging>pom</packaging>
 
   <properties>
+    <maven.compiler.source>1.7</maven.compiler.source>
+    <maven.compiler.target>1.7</maven.compiler.target>
+
     <junit-version>4.12</junit-version>
     <mockito-version>1.10.19</mockito-version>
 
@@ -42,8 +45,6 @@
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-compiler-plugin</artifactId>
         <configuration>
-          <source>1.7</source>
-          <target>1.7</target>
           <optimize>true</optimize>
           <showDeprecation>true</showDeprecation>
           <showWarnings>true</showWarnings>