Upgrade Guava 19.0 to 20.0

Author: yrashk

build.gradle

@@ -96,7 +96,7 @@ dependencies {
     compile 'org.slf4j:slf4j-api:1.7.21'
 
     // Useful utilities
-    compile 'com.google.guava:guava:19.0'
+    compile 'com.google.guava:guava:20.0'
 
     // Unit testing
     testCompile 'org.testng:testng:6.9.10'