Updated CocoaLumberjack

Cocoapods keeps trying to update it when changing other stuff, so update
it on a separate commit in preparation for some other pod changes
Drop duplicate SFHFKeychainUtils instances
Revert "Removed extra instance of SFHFKeychainUtils"

This reverts commit 137f0afa58ceb7563a54be204ec1ca5679a87c2d.
Fixed references to SFHFKeychainUtils
Migrate keychain credentials on launch

Mae sure any keychain item with the kSecAttrAccessibleWhenUnlocked is
updated to kSecAttrAccessibleAfterFirstUnlock so we don't break when
waking up from a notification

fixes #306
Merge pull request #314 from wordpress-mobile/feature/credentials-fix

Fixes keychain access