Update README with required ant version on Java 8

Author: adriaanm

README.md

@@ -62,7 +62,7 @@ scala/
 
 ## Requirements
 
-You'll need a Java SDK (8 or newer), Apache Ant (version 1.8.0 or above), and curl (for `./pull-binary-libs.sh`).
+You'll need a Java SDK (8 or newer), Apache Ant (version 1.9.3 or above), and curl (for `./pull-binary-libs.sh`).
 
 ## Git Hygiene