Update to swift-3.0-RELEASE

Author: norio-nomura

.swift-version

@@ -1 +1 @@
-3.0-PREVIEW-6
+3.0

Sources/Commandant/Errors.swift

@@ -43,11 +43,7 @@ internal func missingArgumentError<ClientError>(_ argumentName: String) -> Comma
 /// Constructs an error by combining the example of key (and value, if applicable)
 /// with the usage description.
 internal func informativeUsageError<ClientError>(_ keyValueExample: String, usage: String) -> CommandantError<ClientError> {
-#if os(Linux)
-	let lines = usage.components(separatedBy: NSCharacterSet.newlines())
-#else
 	let lines = usage.components(separatedBy: .newlines)
-#endif
 
 	return .usageError(description: lines.reduce(keyValueExample) { previous, value in
 		return previous + "\n\t" + value