Dynamic profile photos fail to maintain aspect ratio

[nelsonni]

Profile pictures on the People page were introduced in #6. However, flexbox appears to not be correctly configured for preserving the aspect ratio of the images.

For example, the first image is the EPICLab.github.io/people page open full-screen on my MacOS laptop and the profile images are stretching in the y-axis (height):

The second image is the same page, but with the Developer Console open. Because of the extra pane being open, the available space for flexbox to scale content is less and the images appear to have a proper aspect ratio:

There is a good article on StackOverflow, "Maintain image aspect ratio when changing height", which describes how to resolve this type of issue using CSS and flexbox.