Add the faces of BoG members to the website

**Note:** If you're a new contributor to this repository, refer to [CONTRIBUTING.md](https://github.com/GTBitsOfGood/bog-web/blob/master/CONTRIBUTING.md) before tackling this issue!

The website should show the faces of current and past members in Bits of Good. Project teams could show their members, and other groups could also be shown elsewhere, like on the "About Us" page.

## Action items
- [ ] determine user flow for where faces should show up on the website
- [ ] create mockups for displaying the members of a given team
- [ ] create a MemberCard component that shows a member's picture, name, and role.
- [ ] each MemberCard image should be square
- [ ] (stretch) hovering on the image should change it to a "fun" picture, if available
- [ ] create a Team component that renders set of MemberCards from Contentful data

## Mockups
**[View on Figma for specifics on sizing variables](https://www.figma.com/file/aAThxeD86vXciqJRTmDLjyQG/BitsOfGood-web-redesign?node-id=3197%3A558)**

_(Mockups will be included in the issue as soon as they have been completed)_