Bug: save feature doesn't work on sample

[AndroidDeveloperLB]

v1.6.7

It crashes with this exception:

03-06 15:39:46.202 31590-31590/com.onegravity.rteditor.demo E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.onegravity.rteditor.demo, PID: 31590
    android.os.FileUriExposedException: file:///storage/emulated/0/Android/data/com.onegravity.rteditor.demo/files exposed beyond app through Intent.getData()
        at android.os.StrictMode.onFileUriExposed(StrictMode.java:1960)
        at android.net.Uri.checkFileUriExposed(Uri.java:2348)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:9881)
        at android.content.Intent.prepareToLeaveProcess(Intent.java:9835)
        at android.app.Instrumentation.execStartActivity(Instrumentation.java:1610)
        at android.app.Activity.startActivityForResult(Activity.java:4487)
        at android.support.v4.app.BaseFragmentActivityApi16.startActivityForResult(BaseFragmentActivityApi16.java:54)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:68)
        at android.app.Activity.startActivityForResult(Activity.java:4445)
        at android.support.v4.app.FragmentActivity.startActivityForResult(FragmentActivity.java:751)
        at com.onegravity.rteditor.demo.FileHelper.pickDirectory(FileHelper.java:64)
        at com.onegravity.rteditor.demo.RTEditorActivity.onOptionsItemSelected(RTEditorActivity.java:248)
        at android.app.Activity.onMenuItemSelected(Activity.java:3450)
        at android.support.v4.app.FragmentActivity.onMenuItemSelected(FragmentActivity.java:407)
        at android.support.v7.app.AppCompatActivity.onMenuItemSelected(AppCompatActivity.java:195)
        at android.support.v7.view.WindowCallbackWrapper.onMenuItemSelected(WindowCallbackWrapper.java:108)
        at android.support.v7.app.AppCompatDelegateImplV9.onMenuItemSelected(AppCompatDelegateImplV9.java:674)
        at android.support.v7.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:822)
        at android.support.v7.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:171)
        at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:973)
        at android.support.v7.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:963)
        at android.support.v7.widget.ActionMenuView.invokeItem(ActionMenuView.java:624)
        at android.support.v7.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:150)
        at android.view.View.performClick(View.java:6294)
        at android.view.View$PerformClick.run(View.java:24770)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)