Lock `shoulda-context` to 2.0.0rc4 (#910)
Lock `shoulda-context` to 2.0.0rc4 (#910)

Minor changes that locks us on the 2.0.0 release candidate for
`shoulda-context`. This makes almost no difference to our test suite
except that it removes a long-standing warning for an assigned but
unused variable (which is our last warning!).

See more context here:
https://github.com/thoughtbot/shoulda-context/issues/57#issuecomment-610702695

Co-authored-by: Brandur <00509e3a7b916a959d57487fb812a4576bfbffe3@brandur.org>
stripe/stripe-ruby