Increase 30 seconds lock time after incorrect attempts
As suggested by others in their previous comments, there is currently no application which would do that for you without requiring your phone to be rooted first.

LockScreen Tweakbox (which is a module for the Xposed framework) can do this for you. However you need your phone to be rooted, plus, you will also need to install a custom recovery. 

(Xposed Announcement for Android v5/6 + FAQ)
http://www.xda-developers.com/xposed-framework-for-android-lollipop-is-here/

(Download Xposed Framework for Android v5/6)
http://forum.xda-developers.com/showthread.php?t=3034811

(The actual module, which can only be installed an used once the Xposed Framework is installed and setup properly)
http://forum.xda-developers.com/xposed/modules/mod-lockscreen-tweakbox-various-t2843945

However, if you choose to root your phone and go through this solution, remember to take a proper Nandroid backup and a backup of your current "boot.img". This is important and will save you a headache later on, in case something goes wrong during the process, which sometimes does happen, unfortunately.