Update AUTHORS.md

PPS: I added some *lazy* versions of the proposed changes, though they are tested and work they docstrings need changing and a bit of refactoring is needed too. I only added the other two pull requests since I realized I *could* strictly speaking do so by directly editing files here on github...

PS: I wasn't sure how to make a new branch (tried to push in the standard way with HEAD:my_new_branch_name but got a 403) and thus submit a pull request, I thought the first step was adding my name to the list of authors. Sorry for my misunderstanding :/

Thanks for putting this together, it's a solid repo. I've prepared a commit with the following enhancements:
  - allow 'expand' in searches (both in Issue and JiraClient)
  - add searchIssuesExhaustively to JiraClient and exhaustiveSearch to Issue so search is repeated incrementing startAt until results stop

Working on a commit for tomorrow for an asynchronous JiraClient to permit threading batched requests as well.