Add tests for desired behavior. #19

[ci skip]
Merge branch 'master' into feature/19_pilot_switch_keeps_upgrades
Merge branch 'master' into feature/19_pilot_switch_keeps_upgrades

[ci skip]
Keep upgrades when possible when switching same-ship pilots.

fixes #19
Add test for B-Wing/E #19
Merge branch 'feature/19_pilot_switch_keeps_upgrades'