Allow for **kwargs as the final argument for public methods as needed

[dorono]

This is simply to allow for optional settings in our methods in the future.

By adding **kwargs as the final argument in any of these functions, we can reserve that space for any optional properties we could add, without having to worry about the order of any existing properties.

So the task here to to move all optional arguments to go under the **kwargs object, and then pull those **kwargs properties out into the body of the method.

[hieumt2]

@dorono @sambarnes please review PR #22 updated code for this issue