* Feature: sidecar for ContainerOp
* replace f-string with string format for compatibility with py3.5
* ContainerOp now can be updated with any k8s V1Container attributes as well as sidecars with Sidecar class. ContainerOp accepts PipelineParam in any valid k8 properties.
* WIP: fix conflicts and bugs with recent master. TODO: more complex template with pipeline params
* fix proxy args
* Fixed to work with latest master head
* Added container_kwargs to ContainerOp to pass in k8s container kwargs
* Fix comment bug, updated with example in ContainerOp docstring
* fix copyright year
* expose match_serialized_pipelineparam as public for compiler to process serialized pipeline params
* fixed pydoc example and removed unnecessary ContainerOp.container.parent
* Fix conflicts in compiler tests
* add comments
* relocate functions in compiler to aggregate similar functions; move _build_conventional_artifact as a nested function
* reduce sanitize functions into one in the dsl.
* more comments
* move all sanitization(op name, param name) from dsl to compiler
* sanitize pipelineparam name and op_name; remove format check in pipelineparam
* remove unit test for pipelineparam op_name format checking
* fix bug: correctly replace input in the argument list
* fix bug: replace arguments with found ones
* Sanitize the file_output keys, Matches the param in the args/cmds with the whole serialized param str, Verify both param name and container name
* loosen the containerop and param name restrictions