remove unused dependency on ant (#21)

Signed-off-by: radai-rosenblatt <[email protected]>

Author: radai-rosenblatt

avro-codegen/build.gradle

@@ -11,7 +11,6 @@ plugins {
 dependencies {
     compile project(":avro-migration-helper")
 
-    compile "org.apache.ant:ant:1.10.5"
     compile "commons-io:commons-io:2.6"
     compile "org.apache.logging.log4j:log4j-api:2.11.2"