enhanced gnuplot example in README.md
Merge pull request #13 from ksclarke/enhance-gnuplot-example

enhanced gnuplot example in README.md
added ability to set number of HttpClientBuilder connections
Merge pull request #14 from ksclarke/httpclientbuilder-connections

added ability to set number of HttpClientBuilder connections

Addresses: https://www.pivotaltracker.com/story/show/69266972