Image crop for candidate card with multiple candidacies

[VirginiaDooley]

Issue and Steps to Reproduce

While working on the new Person Page, I noticed the candidate images are awkwardly cropped in some cases.

One candidacy: http://localhost:8000/person/7842/tony-devenish
Many candidacies: http://localhost:8000/person/1478/shaun-bailey

Screenshots

While the image for a candidate with one candidacy looks great:

The image for a candidate with more than one candidacy is less so:

[Heydon]

@VirginiaDooley Okay, I've adjusted this here: cb49071

Bear in mind it’s always going to be an imperfect algorithm to get the card image effect across all viewport dimensions without loads of redundant white-space or stretching the image.