remove cpp pistache petstore test from travis ci

Author: wing328

pom.xml

@@ -928,10 +928,8 @@
                 </property>
             </activation>
             <modules>
-                <module>samples/server/petstore/cpp-pistache</module>
                 <!-- clients -->
                 <module>samples/client/petstore/haskell-http-client</module>
-
                 <module>samples/client/petstore/elm</module>
                 <module>samples/client/petstore/groovy</module>
                 <module>samples/client/petstore/rust</module>