- Switch to use https://github.com/adam-fowler/swift-srp with some modifications
that are local
- Pad g value to equal size of N while calculating clientProof
- Use SHA256(plain-text-password) while computing key using PBKDF2
- Added a unit test with some sample values
We were appending a version without appending a corresponding AvailableXcode, and these two arrays were being zipped later so they wouldn't line up. This change simplifies this method a bit by working on only a single array, and then also moves that appending to the end after the array of Xcodes is created.
