Addresses #75 - Allowing a 'null' argument for WSDL methods that take no arguments
Merge pull request #465 from cklosowski/issue/75

Allow soap calls with no arguments
Updated CONTRIBUTING.md

Added request for accompanying tests in Pull Requests to meet the demands of getting the PR merged.
Merge pull request #472 from herom/master

Updated CONTRIBUTING.md
Avoid creating soap:Header container when there are no children
This time including the matching fixture changes to remove <soap:Header></soap:Header>
Added support for header and security fixtures in request/response tests, and added tests for header optionality
Merge pull request #475 from shelbys/master

Avoid creating soap:Header container when there are no children