Updated to Swift 4.2 package manager

Also updated Interval : Hashable to latest conformance, which uses `Hasher` to combine hash values.  This means that we can no longer expect a certain value from interval.hashValue and thus the test "has a hashValue" needed to modified slightly.

Updated the CocoaPods version to 1.0.1 due to the slight change to Interval's Hashable conformance.

.swift-version

@@ -1 +1 @@
-4.1
+4.2

Package.swift

@@ -1,5 +1,18 @@
+// swift-tools-version:4.2
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
 import PackageDescription
 
 let package = Package(
-    name: "Time"
+    name: "Time",
+    products: [
+        // Products define the executables and libraries produced by a package, and make them visible to other packages.
+        .library( name: "Time", targets: ["Time"] )
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
+        // Targets can depend on other targets in this package, and on products in packages which this package depends on.
+        .target( name: "Time" ),
+        .testTarget( name: "TimeTests", dependencies: ["Time"] )
+    ]
 )

Sources/Time.swift → Sources/Time/Time.swift

@@ -47,10 +47,9 @@ extension Interval : Hashable {
         return lhs != rhs.converted()
     }
 
-    public var hashValue: Int {
-        return timeInterval.hashValue
+    public func hash(into hasher: inout Hasher) {
+        hasher.combine(timeInterval.hashValue)
     }
-
 }
 
 extension Interval {

Tests/TimeTests/Spectre/Expectation.swift

@@ -22,7 +22,7 @@ struct ExpectationFailure : FailureType {
 
 open class Expectation<T> : ExpectationType {
   public typealias ValueType = T
-  open let expression: () throws -> ValueType?
+  public let expression: () throws -> ValueType?
 
   let file: String
   let line: Int

Tests/TimeTests/TimeSpec.swift

@@ -34,7 +34,7 @@ func testTime() {
         }
         $0.it("has a hashValue") {
             let interval = Interval<OneSecond>(10)
-            try expect(interval.hashValue) == interval.timeInterval.hashValue
+            try expect(interval.hashValue) != 0
         }
     }
 

TimeIntervals.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name         = "TimeIntervals"
-  s.version      = "1.0.0"
+  s.version      = "1.0.1"
   s.summary      = "Type-safe time calculations for Swift."
   s.description  = <<-DESC
     Type-safe time calculations for Swift, powered by generics.