Copy all Strings received from agentcore instead of using raw pointer (…

…#126)

* Add debug to diagnose test crash on Travis

* Try copying bad string

* remove debug

Sources/SwiftMetrics/SwiftMetrics.swift

@@ -66,7 +66,10 @@ private func receiveAgentCoreData(cSourceId: UnsafePointer<CChar>, cSize: CUnsig
   }
   let source = String(cString: cSourceId)
   if source != "api" {
-    let message = String(bytesNoCopy: data, length: size, encoding: String.Encoding.utf8, freeWhenDone: false) ?? ""
+    let opaquePointer = OpaquePointer(data)
+    let cstrPointer = UnsafePointer<CChar>(opaquePointer)
+
+    let message = String(cString:cstrPointer) ?? ""
     if swiftMon != nil {
       swiftMon!.raiseCoreEvent(topic: source, message: message)
     }