CFY-849 added the 'allow_custom_parameters' flag for 'execute-workflow' API
CFY-849 fixed the passing of 'allow_custom_parameters' parameter on Execute call
Merge pull request #24 from cloudify-cosmo/feature/CFY-849-add-parameter-for-specifying-if-custom-parameters-to-execution-is-allowed

Feature/cfy 849 add parameter for specifying if custom parameters to execution is allowed