message: Upgrade mapstruct to 1.2.0.Final
diff: <!-- Dependency versions -->
  <jhipster-dependencies.version>0.1.4</jhipster-dependencies.version>
  - <mapstruct.version>1.1.0.Final</mapstruct.version>
  + <mapstruct.version>1.2.0.Final</mapstruct.version>
  <!-- The spring-boot version should match the one managed by
  https://mvnrepository.com/artifact/io.github.jhipster/jhipster-dependencies/${jhipster-dependencies.version} -->
  <spring-boot.version>1.5.9.RELEASE</spring-boot.version>
  