Add Xcode 9.2 compatibility

[crossle]

clone the master branch, run pod install

[!] Unable to find a target named `LibSignalProtocolSwift iOS`, did find `SignalProtocol iOS`, `SignalProtocol macOS`, `SignalProtocol tvOS`, `SignalProtocol watchOS`, and `SignalProtocol Tests`.

Other compile error, UnsafeMutableRawPointer allocate and deallocate can not compile on Xcode 9.2
should use this

let ptr = UnsafeMutableRawPointer.allocate(bytes: dataLength, alignedTo: MemoryLayout<UInt8>.alignment)
        defer { ptr.deallocate(bytes: dataLength, alignedTo: MemoryLayout<UInt8>.alignment) }

[christophhagen]

The missing targets are fixed now.

Unfortunately I can't fix the other error right now. The function deallocate(bytes:alignedTo:) is deprecated in Xcode 9.3 SDK and replaced by deallocate(). I'm not aware of a check to see which Xcode SDK is being used, or any other way to fix this.

Any help resolving this is appreciated.

[crossle]

BTW, libsignal-protocol-swift is it stable? i think the Swift API should like libsignal-protocol-java

[christophhagen]

At the moment libsignal-protocol-swift only works when importing the framework directly. Cocoapods installation fails due to some problems with the module maps not being found. I'm trying to resolve the issue, probably by moving to SignalProtocolC for the C library. But this will take a few days, I'm a little busy at the moment.

[yudiz-mahavirsinh]

hey @christophhagen any update on libsignal-protocol-swift pods ?