Features/add process service

[anilnatha]

This PR contains the following updates:

• Addition of a process service through which users may interact with SPS to perform operations like get a list of processes and get a list of jobs for a given process.
• Addition of process and job classes to facilitate additional functionality using SPS like, executing a process which returns a job, getting the status or results of a job, and dismissing a job.

Note: This PR brings to light that we do not have an endpoint currently to fetch a single process's information. A user is currently required to fetch all processes information to get a single process's information even if they know the process's name.

[anilnatha]

@mike-gangl I could use your guidance on writing tests in test_unity_py.py.

[anilnatha]

@mike-gangl Hold off on the review, I found one update I'd like to make to the Job class.

[anilnatha]

@mike-gangl please proceed with the PR review. I wanted to add an update for the jobs class to account for results returned by SPS, but at the moment those aren't being populated so I don't have the information I need to build out that data structure.

[anilnatha]

@mike-gangl I'm proceeding with the merging of the addition of the process service. There are some additional enhancements that still need to be made that we'll catalog in tickets and as changes are made to WPS-T API.