fix(web): add fallback files in case lib isn't available for a platform (#205)

Will throw an error in case the lib does not support the
currently running platform. 

Fixes problem where metro will fail to even start
without non-targetted (.ios.js/.android.js) files

Author: hsjoberg

src/authenticate.js

@@ -0,0 +1,7 @@
+import { Platform } from 'react-native';
+
+export default () => {
+  return new Promise((_, reject) => {
+    reject(new Error(`react-native-fingerprint-scanner is not available for ${Platform.OS}`))
+  });
+}

src/isSensorAvailable.js

@@ -0,0 +1,7 @@
+import { Platform } from 'react-native';
+
+export default () => {
+  return new Promise((_, reject) => {
+    reject(new Error(`react-native-fingerprint-scanner is not available for ${Platform.OS}`))
+  });
+}

src/release.js

@@ -0,0 +1,7 @@
+import { Platform } from 'react-native';
+
+export default () => {
+  return new Promise((_, reject) => {
+    reject(new Error(`react-native-fingerprint-scanner is not available for ${Platform.OS}`))
+  });
+}