Bump version to 0.2.0 (#119)

diff --git a/gradle.properties b/gradle.properties
index 2afbc1a..3e4584e 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -17,4 +17,4 @@
 # under the License.
 #
 
-version=0.1.1-SNAPSHOT
+version=0.2.0