Removal of 1.6 requirements

[AndreRl]

As 1.6 is EOL and 1.8 has been out for the last few years, I no longer see a reason to mention MyBB's 1.6 requirements. If necessary, users should see 1.6's old documentation.

It may also be wise to bump the recommended PHP version to 7.0 or the planned minimum PHP version in preparation for 1.9x. Opinions?

[Eldenroot]

I agree - we should recommend to user to use newer php,but mention that php 5.4 is still supported but will be discontinued in near future

[effone]

Oh my ¡