Build fails in Go 1.13 due to older golang-lint presense in mod file

[bbrks]

The project doesn't build under Go 1.13 out of the box due to an incompatible/older golangci-lint dependency in the mod file (golangci/golangci-lint#652)

$ git clone git@github.com:schweikert/fping-exporter.git
Cloning into 'fping-exporter'...
remote: Enumerating objects: 40, done.
remote: Counting objects: 100% (40/40), done.
remote: Compressing objects: 100% (30/30), done.
remote: Total 40 (delta 14), reused 32 (delta 9), pack-reused 0
Receiving objects: 100% (40/40), 278.57 KiB | 352.00 KiB/s, done.
Resolving deltas: 100% (14/14), done.
$ cd fping-exporter/
$ go build
go: github.com/golangci/golangci-lint@v1.17.1 requires
	github.com/go-critic/go-critic@v0.0.0-20181204210945-1df300866540: invalid pseudo-version: does not match version-control timestamp (2019-05-26T07:48:19Z)