Update Firebase dependency and remove FirebaseSettings (#36)

Author: stephengilroy-grx

Package.resolved

@@ -7,8 +7,8 @@ let package = Package(
     name: "SegmentFirebase",
     platforms: [
         .macOS("10.15"),
-        .iOS("13.0"),
-        .tvOS("13.0"),
+        .iOS("15.0"),
+        .tvOS("15.0"),
         .watchOS("7.1")
     ],
     products: [
@@ -28,7 +28,7 @@ let package = Package(
 		.package(
 			name: "Firebase",
 			url: "https://github.com/firebase/firebase-ios-sdk",
-			from: "11.1.0"
+			from: "12.0.0"
 		)
     ],
     targets: [

Package.swift

@@ -57,12 +57,8 @@ open class FirebaseDestination: DestinationPlugin {
         // we've already set up this singleton SDK, can't do it again, so skip.
         guard type == .initial else { return }
 
-        guard let firebaseSettings: FirebaseSettings = settings.integrationSettings(forPlugin: self) else { return }
-        if let deepLinkURLScheme = firebaseSettings.deepLinkURLScheme {
-            FirebaseOptions.defaultOptions()?.deepLinkURLScheme = deepLinkURLScheme
-            analytics?.log(message: "Added deepLinkURLScheme: \(deepLinkURLScheme)")
-        }
-        
+        guard settings.hasIntegrationSettings(forPlugin: self) else { return }
+
         // First check if firebase has been set up from a previous settings call
         if (FirebaseApp.app() != nil) {
             analytics?.log(message: "Firebase already configured, skipping")
@@ -217,12 +213,6 @@ extension FirebaseDestination {
         }
     }
 }
-
-
-private struct FirebaseSettings: Codable {
-    let deepLinkURLScheme: String?
-}
-
 private extension FirebaseDestination {
 
     static let mappedValues = ["Product Clicked": FirebaseAnalytics.AnalyticsEventSelectItem,