* move set_module_args to units.modules.utils
* unit tests: reuse set_module_args
* unit tests: mock exit/fail_json in module.utils.ModuleTestCase
* unit tests: use module.utils.ModuleTestCase
* unit tests: fix 'import shadowed by loop variable'
* removes cli functions from shared lib
* adds cli functions to junos_netconf module
* statically pins junos_netconf to cli transport
* all other modules use netconf transport
* adds command rpc function to junos shared