Cvprac

* Validated system tests up through CVP 2021.1.1
* Added new method for searching for a device by serial number
* Added form parameter to update_configlet_builder method
* Added parameter to apply_configlets_to_device to allow reordering of existing configlets
* Added new examples of cvprac usage in docs/labs
* Added flag to enable searching by hostname to get_device_by_name function

* Fix client logout function
* Mask localhost/127.0.0.1 with node IP for configlet builder scripts
* Add client handling for new resource API REST bindings that return multiple objects in response data
* Add API method update_configlet_builder and test
* Added function and test for API endpoint updateReconcileConfiglet.do
* Remove CVaaS un/pw login. Only API tokens for CVaaS now
* Add exception when attempting to delete container with children for CVP versions 2020.1 and beyond

* Never fallback to HTTP in case of connection failure
* Add client handling for CVP 2020.3. Update get_logs_by_id for CVP 2020.3
* Add more detailed docstring to check_compliance function
* Update get_device_by_name and get_device_by_mac to use search_topology instead of get_inventory
* Add general support for using api tokens for access to REST API
* Updated/Enhanced user APIs
* Update approve_change_control to provide current time timestamp as default
* Updated and enhanced system tests for new CVP versions and features

- Add support for CVP 2020.X.
- Add delete function to client for DELETE REST API
- Add methods for user management.
- Improve API version handling
- Add support for CVaaS
- Improve efficiency of get_inventory and get_containers
- Add functions for getConfigletsAndAssociatedMappers.do and getImageBundleByContainerId.do APIs
- Update documentation
- Additional enhancements and bug fixes.

* Fix Issue 103 (cvprac is using the incorrect version of the API for 2018.1.x)

- Add support for CVP 2019.x.
- Add methods for adding/removing configlets to/from containers.
- Add method for resetting a device back to Undefined container.
- Add methods for configlet builder handling.
- Add methods for Change Controls and handle CVP 2019.x changes.
- Additional enhancements and bug fixes.