Suppress warnings about unnecessary casts

These casts are necessary unless we require Rust 1.48.
10 jobs for unnecessary-casts in 23 minutes and 21 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Check
passed #1141040
check

00:01:42

 
  Lint
passed #1141042
clippy

00:03:11

passed #1141041
fmt

00:01:24

 
  Unit Test
manual #1141044
allowed to fail manual
cargo_bench
passed #1141043
cargo_test

00:04:40

 
  Acceptance Test
passed #1142645
opensuse:tumbleweed

00:15:20

passed #1141045
opensuse:tumbleweed

00:05:41

 
  Cross Distro
passed #1141047
manual
debian:testing

00:16:53

passed #1141046
manual
fedora:latest

00:14:16

 
  Release
manual #1141048
allowed to fail manual
distcheck