Don't show automatic credit phrase where qualifying years are 30 or more
Remove redundant method
Fix different d.o.b. same pension date bug

Factcheck revealed a bug where people with the same pension date
and a different date of birth who were within 4 months and a day
from state pension date were presented with different answers.
Added flow tests with the factcheck inputs.
Merge pull request #582 from alphagov/state_pension_calc_bugfixes

State pension calc bugfixes