Add Rebecca to alumni

[hlapp]

This came up in the course of #40. We'll need the following pieces of information about her:

• Bio (brief), including a succinct statement on what she did for the project, and where she is now.
• Picture ((160x160px, or higher, but square)
• Github, Twitter, ORCID or Google Scholar to the extent available

[hlapp]

@ncellinese to provide the information as per above, then reassign to me.