chore(deps): bump github.com/gofrs/flock in /plugins/ps

Bumps [github.com/gofrs/flock](https://github.com/gofrs/flock) from 0.8.0 to 0.8.1.
- [Release notes](https://github.com/gofrs/flock/releases)
- [Commits](https://github.com/gofrs/flock/compare/v0.8.0...v0.8.1)

---
updated-dependencies:
- dependency-name: github.com/gofrs/flock
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

plugins/ps/go.mod

@@ -7,7 +7,7 @@ require (
 	github.com/dokku/dokku/plugins/common v0.0.0-00010101000000-000000000000
 	github.com/dokku/dokku/plugins/config v0.0.0-00010101000000-000000000000
 	github.com/dokku/dokku/plugins/docker-options v0.0.0-00010101000000-000000000000
-	github.com/gofrs/flock v0.8.0
+	github.com/gofrs/flock v0.8.1
 	github.com/otiai10/copy v1.9.0
 	github.com/ryanuber/columnize v1.1.2-0.20190319233515-9e6335e58db3
 	github.com/spf13/pflag v1.0.5

plugins/ps/go.sum

@@ -2,8 +2,8 @@ github.com/codegangsta/inject v0.0.0-20150114235600-33e0aa1cb7c0 h1:sDMmm+q/3+Bu
 github.com/codegangsta/inject v0.0.0-20150114235600-33e0aa1cb7c0/go.mod h1:4Zcjuz89kmFXt9morQgcfYZAYZ5n8WHjt81YYWIwtTM=
 github.com/codeskyblue/go-sh v0.0.0-20190412065543-76bd3d59ff27 h1:HHUr4P/aKh4quafGxDT9LDasjGdlGkzLbfmmrlng3kA=
 github.com/codeskyblue/go-sh v0.0.0-20190412065543-76bd3d59ff27/go.mod h1:VQx0hjo2oUeQkQUET7wRwradO6f+fN5jzXgB/zROxxE=
-github.com/gofrs/flock v0.8.0 h1:MSdYClljsF3PbENUUEx85nkWfJSGfzYI9yEBZOJz6CY=
-github.com/gofrs/flock v0.8.0/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
+github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
+github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/joho/godotenv v1.2.0 h1:vGTvz69FzUFp+X4/bAkb0j5BoLC+9bpqTWY8mjhA9pc=
 github.com/joho/godotenv v1.2.0/go.mod h1:7hK45KPybAkOC6peb+G5yklZfMxEjkZhHbwpqxOKXbg=