Fix various CI issues (OpenAPITools#1722)

* fix shippable failure

* fix warning in javadoc, test ruby in shippable

* update mvn command

* move ruby test to circleci

* remove additional option

pom.xml

@@ -1054,7 +1054,6 @@
                 <module>samples/client/petstore/typescript-angular-v4.3/npm</module>
                 <module>samples/client/petstore/typescript-angular-v6-provided-in-root</module>
                 <!--<module>samples/client/petstore/bash</module>-->
-                <module>samples/openapi3/client/petstore/ruby</module>
                 <module>samples/server/petstore/rust-server</module>
             </modules>
         </profile>
@@ -1160,6 +1159,7 @@
             </activation>
             <modules>
                 <!-- clients -->
+                <module>samples/openapi3/client/petstore/ruby</module>
                 <!-- test java-related projects -->
                 <module>samples/client/petstore/scala-akka</module>
                 <module>samples/client/petstore/scala-httpclient</module>

shippable.yml

@@ -37,7 +37,7 @@ build:
     - elixir --version
     - mix --version
     # test samples defined in pom.xml
-    - mvn --quiet verify -P samples.shippable
+    - mvn --quiet verify -P samples.shippable -Dmaven.javadoc.skip=true
     # generate all petstore samples (client, servers, doc)
     - ./bin/run-all-petstore
     # generate all petstore samples (openapi3)