Address registration tests

[shaun-technovation]

The following tests should be updated/fixed, or removed:

Students signing up location form lets you change its guess
  # Temporarily skipped with xdescribe
  # ./spec/system/student/signup_spec.rb:52

Students signing up authenticating logs in okay with the email / password used during signup
  # Temporarily skipped with xdescribe
  # ./spec/system/student/signup_spec.rb:5

Activate your email to sign up Register the signup attempt on sign up
  # Temporarily disabled with xfeature
  # ./spec/features/activate_email_for_signup_spec.rb:27

Activate your email to sign up Activate your email for signing up
  # Temporarily disabled with xfeature
  # ./spec/features/activate_email_for_signup_spec.rb:6

Student team submissions See live pitch event submission pieces on TOC
  # Temporarily disabled with xscenario
  # ./spec/features/mentor/submission_spec.rb:157

Mentors signing up authenticating logs in okay with the email / password used during signup
  # Temporarily skipped with xdescribe
  # ./spec/system/mentor/signup_spec.rb:5

[shaun-technovation]

For the "signup" and "signup flow" related specs, I removed those since neither of those things are being used now.

And one non-signup test made it into this issue:

./spec/features/mentor/submission_spec.rb:157

I moved that one into #3851.

[shaun-technovation]

Moving this one to "Ready to Deploy" since there is nothing to test for this one. 👍