Add Helper function to generate random slug

PR link: https://github.com/QuorumUS/walawala/pull/9

New Features

• What feature(s) did you add / how I implemented?
  Added a helper function to generate a random slug of the form dkfiedk59dlskdjfi with the ability to choose a length and a charset. The function uses the random library, and random.SystemRandom() guarantees a random slug. We need to generate urls to access certain pages in our applications, and we wanted urls of the form /url/thing/dkaldkdfoielai29fj/. This PR allows us to import our function anywhere in our Django codebase.
  This is the important line: https://github.com/QuorumUS/walawala/pull/9/files/d68a5c78a9cd5d6d4934272dc159e206521fe075#diff-91adb49ec779b8abb9a0c129bdf2146aR121

New Projects

• What is the project about?
  This project is a collection of mostly string helper functions that reduce code duplication and localizes logic. We do a lot of string parsing and processing, and we found that over time we were writing a lot of little helper functions to do our jobs. Abstracting out that logic into a seperate repo is a more maintainable long term solution.
• Technology Stack
  Briefly list the used technologies and languages and other technical requirements.
  The only technology here is Python
• Roadmap
  I'd like to make this repo more accessible to the rest of the open source community by adding more docstrings and general documentation, which would include a list of all helper functions available in the library.
• How to contribute?
  Anyone can reach out to me via github, twitter (@jmares93), or jmares93@gmail.com.

Note: I know this PR is a little older than 7 days, but its my first contribution so I wanted to try and post it!