Change Group Membership as the Result of an Evaluation

[mbillow]

Basically, we should check if someone is in the Intro Members group and if they fail Spring Evals they should be removed from both that group and the Active group when they fail.

Stretch goal: We should also remove people from Intro Members if they pass a Spring Eval.

[mbillow]

Per @liam-middlebrook, we should also add them to the "Failed" group.

[liam-middlebrook]

This needs to be generalized. Members who fail a Spring Evals (or resign throughout the year) should be placed into the bad_standing group.

[devinmatte]

#223 Addressed some of these points