Update READMEs with new integration test details
Link to contributing guidelines

...instead of duplicating some of that info in the README. Also remove some references that weren't used.
Rename the integration test that tests net_launch

As per the standard in the other gems.
The README was wrong about required parameters

These tests only require two parameters to be set.

Add the template config yaml file, add the file itself to gitignore and update the integration tests README to indicate what the required parameters are.
Use vCloud Tools tester instead of env vars
Update Jenkins files so CI works

This obtains the configuration from GitHub Enterprise. It also cleans up before and after itself.
Merge pull request #33 from gds-operations/use-tools-tester

[#71835604] Use vCloud Tools Tester instead of environment variables
Add a validation schema for `vcloud-net-launch`

Schema is based on these sources:

VMWare documentation:
http://pubs.vmware.com/vcd-51/index.jsp?topic=%2Fcom.vmware.vcloud.api.reference.doc_51%2Fdoc%2Findex.html

The 'orgVdcNetwork' generator in Fog:
https://github.com/fog/fog/blob/master/lib/fog/vcloud_director/generators/compute/org_vdc_network.rb

vCloud Core's `org_vdc_network.rb`:
https://github.com/gds-operations/vcloud-core/blob/master/lib/vcloud/core/org_vdc_network.rb
Use `let` rather than `let!` in Rspec tests

After discussion with @dancarley (who committed this code in
96441e5f6d26778f983dcdc63efd7c1df8638ba2), I can't see any reason for
these `let!` declarations not to lazy-load using `let` (without the
trailing exclamation mark).

The tests also pass without the exclamation mark.
DRY up spec tests using `let`