Merge pull request #18 from jimregan/antlr4.2

antlr 4.1 breaks with JDK 1.8
diff --git a/pom.xml b/pom.xml
index db97761..0e7477f 100644
--- a/pom.xml
+++ b/pom.xml
@@ -20,12 +20,12 @@
     <dependency>
       <groupId>org.antlr</groupId>
       <artifactId>antlr4-runtime</artifactId>
-      <version>4.1</version>
+      <version>4.2</version>
     </dependency>
     <dependency>
       <groupId>org.antlr</groupId>
       <artifactId>antlr4-maven-plugin</artifactId>
-      <version>4.1</version>
+      <version>4.2</version>
     </dependency>
     <dependency>
       <groupId>org.antlr</groupId>
@@ -158,7 +158,7 @@
 	     recipe is based on http://stackoverflow.com/questions/15310628/ customize-maven-to-automatically-create-antlr4-grammar-java-files-on-build -->
 	<groupId>org.antlr</groupId>
 	<artifactId>antlr4-maven-plugin</artifactId>
-	<version>4.1</version>
+	<version>4.2</version>
 	<executions>
 	  <execution>
 	    <id>poliqarpplus</id>