extract property for maven exec plugin version

easyrules-samples/pom.xml

@@ -87,7 +87,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
-                        <version>1.3</version>
+                        <version>${maven-exec-plugin.version}</version>
                         <configuration>
                             <mainClass>org.easyrules.samples.helloworld.Launcher</mainClass>
                             <systemProperties>
@@ -109,7 +109,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
-                        <version>1.3</version>
+                        <version>${maven-exec-plugin.version}</version>
                         <configuration>
                             <mainClass>org.easyrules.samples.rulePriority.Launcher</mainClass>
                             <systemProperties>
@@ -131,7 +131,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
-                        <version>1.3</version>
+                        <version>${maven-exec-plugin.version}</version>
                         <configuration>
                             <mainClass>org.easyrules.samples.order.Launcher</mainClass>
                             <systemProperties>
@@ -153,7 +153,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
-                        <version>1.3</version>
+                        <version>${maven-exec-plugin.version}</version>
                         <configuration>
                             <mainClass>org.easyrules.samples.scheduling.Launcher</mainClass>
                             <systemProperties>
@@ -175,7 +175,7 @@
                     <plugin>
                         <groupId>org.codehaus.mojo</groupId>
                         <artifactId>exec-maven-plugin</artifactId>
-                        <version>1.3</version>
+                        <version>${maven-exec-plugin.version}</version>
                         <configuration>
                             <mainClass>org.easyrules.samples.spring.Launcher</mainClass>
                             <systemProperties>

pom.xml

@@ -41,6 +41,7 @@
         <maven-compiler-plugin.version>3.3</maven-compiler-plugin.version>
         <maven-surefire-plugin.version>2.19</maven-surefire-plugin.version>
         <maven-javadoc-plugin.version>2.10.3</maven-javadoc-plugin.version>
+        <maven-exec-plugin.version>1.4.0</maven-exec-plugin.version>
     </properties>
 
     <scm>