Sample code and getClient() does not match gp service properly

[srl295]

As noted in an internal report, "Here the cfenv AppEnv method "getServiceCreds" is used to match the service name based on the regular expression spec, and will return its Credentials property if matched. (see https://www.npmjs.com/package/cfenv#appenv-getservicecreds-spec .) "

Basically, as is the service is expecting the service name to match gp-* when it should look for the label.

See: cloudfoundry-community/node-cfenv#3

Todo:

• Document how to specify the service name to match
• look at how to match gp-* as a label
• contribute upstream to cfenv?

[srl295]

Note that in the sample code this problem was masked because of IBM-Cloud/gp-nodejs-sample#3