Don't build the Swift binary on publish time anymore

With macOS 10.14.4, Swift CLI binaries no longer contains the support Swift support libraries.

For now, we just use the binary before this was the case so it continues working without issues.

At some point we'll be forced to require macOS 10.14.4 or later though.

Fixes #53

package.json

@@ -15,7 +15,7 @@
 	"scripts": {
 		"test": "xo && ava && tsd",
 		"build": "swift build --configuration=release --static-swift-stdlib && mv .build/release/active-win main",
-		"prepublishOnly": "npm run build"
+		"//prepublishOnly": "npm run build"
 	},
 	"files": [
 		"index.js",