Unpin the cocoapods instructions from Nimble 6.0.0
Unpin the cocoapods instructions from Nimble 6.0.0

As this leads to confusion when the library won't build in newer versions of swift!
phatblat/Nimble,Quick/Nimble,Quick/Nimble,Quick/Nimble,phatblat/Nimble,phatblat/Nimble