Merge branch 'release-v1.18'

* release-v1.18:
  Finish releasing v1.18.0
  Releasing v1.18.0

Author: rjrjr

gradle.properties

@@ -8,7 +8,7 @@ android.useAndroidX=true
 systemProp.org.gradle.internal.publish.checksums.insecure=true
 
 GROUP=com.squareup.workflow1
-VERSION_NAME=1.18.0-SNAPSHOT
+VERSION_NAME=1.19.0-SNAPSHOT
 
 POM_DESCRIPTION=Square Workflow