Allow value to be object type in ServiceConfig

[ekasitk]

This PR allows values in ServiceConfig to be an integer or any other types than just a string. So the generated JSON is correctly formatted according to the type of value.

[vinodborole]

@ekasitk can you please share the use case for this change request?

[ekasitk]

When setting service parameters, values can be string or number.

  ServiceConfig hdfsConf = Builders.serviceConfig()
                              .set("dfs.namenode.logging.level","info")
                              .set("dfs.replication",1);
 Cluster cluster = Builders.cluster().name("test")
                        .addServiceConfig("HDFS",hdfsConf);

This PR permits ServiceConfig.set() to accept number and generate the json like:
{
"name" : "test",
"cluster_configs" : {
"HDFS" : {
"dfs.namenode.logging.level" : "info",
"dfs.replication" : 1
}
},
"hadoop_version" : "1.6.2"
}

Otherwise, all values will always be treated as string, i.e. "dfs.replication" : "1", which is not complied well to the API. Ref: https://developer.openstack.org/api-ref/data-processing/?expanded=show-details-of-a-cluster-detail.

[auhlig]

Makes sense. Or not @vinodborole?
But a test for a more complex config would be nice.

[vinodborole]

I agree @auhlig as per the openstack doc this change request makes sense. A test for a more complex config will be necessary in order to be sure nothing else breaks. @ekasitk is it possible for you to add this test case along with this PR?

[ekasitk]

@vinodborole @auhlig
I can add some test cases but it will take a while.

[vinodborole]

@ekasitk sure not a problem

[ekasitk]

@vinodborole @auhlig
I've added some test cases for this PR. Please kindly check.

[vinodborole]

LGTM @auhlig what do you think?

[auhlig]

LGTM. Many thanks @ekasitk