Merge pull request #9 from master-atul/feature/new-extraction-method

This fixes https://github.com/master-atul/react-native-appstore-version-checker/issues/8

v2.4.0 will have the fix !!

Nothing to do . Just upgrade the package and use it
the default way

```getAppstoreAppVersion('com.supercell.clashofclans') //put any apps packageId here
.then((appVersion) => {
  console.log('clashofclans android app version on playstore', appVersion);
})
.catch((err) => {
  console.log('error occurred', err);
});```

android/src/main/java/com/masteratul/RNAppstoreVersionCheckerModule.java

@@ -28,8 +28,13 @@ public void appVersionExtractor(
             Callback errorCallback) {
         try {
             Document doc = Jsoup.connect(url).get();
-            Elements versionElement = doc.select(extractor);
-            String versionText = versionElement.text();
+            String versionText;
+            if(extractor.equalsIgnoreCase("")){
+                versionText = doc.getElementsContainingOwnText("Current Version").parents().first().getAllElements().last().text();
+            }else{
+              versionText = doc.select(extractor).text();
+            }
+            // https://stackoverflow.com/a/49924787/2881112
             successCallback.invoke(versionText);
         } catch (Exception e) {
             errorCallback.invoke(e.getMessage());

src/versionChecker.android.js

@@ -1,10 +1,10 @@
 import {NativeModules} from 'react-native';
 import {get} from './fetcher';
+const getAppstoreAppVersion = (id, options = { jquerySelector: "" }) => {
 
-const getAppstoreAppVersion = (id, { jquerySelector = '[itemprop=\'softwareVersion\']' }) => {
   const url = `https://play.google.com/store/apps/details?id=${id}`;
   return new Promise((resolve, reject) => {
-    NativeModules.RNAppstoreVersionChecker.appVersionExtractor(url,jquerySelector,resolve, reject);
+    NativeModules.RNAppstoreVersionChecker.appVersionExtractor(url,options.jquerySelector,resolve, reject);
   });
 };