redis extension

[Remi Collet]

Upcoming version 1.4.0 (RC1 is released) introduce some BC break, so to
give user choice to update or keep old API, I create a new package

So

Fedora 26:
    php-pecl-redis version 3.x

Fedora 27-28:
    php-pecl-redis version 3.x
    php-pecl-redis4 version 4.x

Fedora 29+
    php-pecl-redis4 version 4.x

So, I will retire "php-pecl-redis" from rawhide after GA release and
after F28 branching.

Remi.