Release 2062
I previously merged (and reverted) a change to remove date of birth from the candidate sign up. Unfortunately, we saw an exception where a user was in the middle of their sign up journey (I shouldn't have reverted because it was too late, but I wasn't sure what was going on)
To fix - Leave the date of birth attribute in the PersonalInformation model to support users who are half-way through their sign up journey, then remove it in a few hours. Have tested this by swapping from master and this branch after inputting a date of birth, then completing the sign up process.