go.mod: bump golang.org/x/sys from 0.4.0 to 0.5.0

Bumps [golang.org/x/sys](https://github.com/golang/sys) from 0.4.0 to 0.5.0.
- [Release notes](https://github.com/golang/sys/releases)
- [Commits](golang/sys@v0.4.0...v0.5.0)

---
updated-dependencies:
- dependency-name: golang.org/x/sys
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

go.mod

@@ -4,5 +4,5 @@ go 1.13
 
 require (
 	github.com/tklauser/numcpus v0.6.0
-	golang.org/x/sys v0.4.0
+	golang.org/x/sys v0.5.0
 )

go.sum

@@ -1,5 +1,5 @@
 github.com/tklauser/numcpus v0.6.0 h1:kebhY2Qt+3U6RNK7UqpYNA+tJ23IBEGKkB7JQBfDYms=
 github.com/tklauser/numcpus v0.6.0/go.mod h1:FEZLMke0lhOUG6w2JadTzp0a+Nl8PF/GFkQ5UVIcaL4=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
-golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=