evil-commands.el: require seq lib

Fixes warnings like:

    evil-commands.el:5200:1:Error: the following functions are not known to be defined: seq-find

Author: Hi-Angel

evil-commands.el

@@ -36,6 +36,7 @@
 (require 'evil-vars)
 (require 'cl-lib)
 (require 'reveal)
+(require 'seq)
 
 (declare-function imenu--in-alist "imenu")