flip1995: Stepping down from the reviewer rotation

A step I was trying to avoid for way too long, but sadly necessary now. I hope I
can come back stronger in a few months.

Author: flip1995

triagebot.toml

@@ -17,9 +17,9 @@ contributing_url = "https://github.com/rust-lang/rust-clippy/blob/master/CONTRIB
 
 [assign.owners]
 "/.github" = ["@flip1995"]
+"/book" = ["@flip1995"]
 "/util/gh-pages" = ["@xFrednet"]
 "*" = [
-    "@flip1995",
     "@Manishearth",
     "@llogiq",
     "@giraffate",