0.1.5

• Java 7
• Replace OSGi plugin with biz.aQute.bnd
• update to Gradle 5.6.3
• lint / errorprone, and fixes for reported issues
• TravisCI
• bump json-schema-validator version to 2.2.12
• bump mockito-core version to 2.28.2
• bump avro to 1.9.1
• add explicit json-schema-core 1.2.12
• add explicit jackson-databind 2.9.9