FMT: Java/Swift; also updates gradle plugin to 3.1.2 to address issue #65

Author: ghigh

android/build.gradle

@@ -8,7 +8,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.0'
+        classpath 'com.android.tools.build:gradle:3.1.2'
     }
 }
 

android/src/main/java/com/flutter_webview_plugin/WebviewManager.java

@@ -162,7 +162,7 @@ boolean canGoBack() {
     boolean canGoForward() {
         return webView.canGoForward();
     }
-	void hide(MethodCall call, MethodChannel.Result result) {
+    void hide(MethodCall call, MethodChannel.Result result) {
         if (webView != null) {
             webView.setVisibility(View.INVISIBLE);
         }

ios/Classes/FlutterWebviewPlugin.m

@@ -46,7 +46,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
     } else if ([@"resize" isEqualToString:call.method]) {
         [self resize:call];
         result(nil);
-	} else if ([@"reloadUrl" isEqualToString:call.method]) {
+    } else if ([@"reloadUrl" isEqualToString:call.method]) {
         [self reloadUrl:call];
         result(nil);	
     } else if ([@"show" isEqualToString:call.method]) {