You can change this in the home button settings - select 'Rest to unlock'
No that gets you round having to press the button, I do that on my 7 but for example on the other halfs 6S I don't have a fingerprint stored so I need to use the passcode, that was easy before, I just did a swipe to unlock but as far as I can tell now all I can do is fail the fingerprint check and then put the pin code in. It's a bit odd but I guess partly because I've been so used to swipe to unlock.. for like 9 years lol.