Bump github.com/mackerelio/mackerel-client-go from 0.6.0 to 0.8.0

Bumps [github.com/mackerelio/mackerel-client-go](https://github.com/mackerelio/mackerel-client-go) from 0.6.0 to 0.8.0.
- [Release notes](https://github.com/mackerelio/mackerel-client-go/releases)
- [Commits](mackerelio/mackerel-client-go@v0.6.0...v0.8.0)

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

go.mod

@@ -12,7 +12,7 @@ require (
 	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/mackerelio/go-osstat v0.0.0-20190712033226-e9f3fb840708
 	github.com/mackerelio/golib v0.0.0-20190411032134-c87047ca454e
-	github.com/mackerelio/mackerel-client-go v0.6.0
+	github.com/mackerelio/mackerel-client-go v0.8.0
 	github.com/mattn/go-encoding v0.0.2
 	github.com/mattn/go-isatty v0.0.9 // indirect
 	github.com/motemen/go-cli v0.0.0-20180105012931-9961a876eb5f

go.sum

@@ -36,6 +36,8 @@ github.com/mackerelio/golib v0.0.0-20190411032134-c87047ca454e h1:MwWzFCq2tENDy2
 github.com/mackerelio/golib v0.0.0-20190411032134-c87047ca454e/go.mod h1:kbqYA8VcFqcMt07v+GPSZQwqtwc7Wr0V0vzxUNMrk7E=
 github.com/mackerelio/mackerel-client-go v0.6.0 h1:Zzer4jmHdDucOpO5Qco7r0MdIg0TExbQem1nLX8dtYE=
 github.com/mackerelio/mackerel-client-go v0.6.0/go.mod h1:/FVnUK7nsg/MEBpIVOCZLYzdIwY5mg/SyAlXDnxVcAI=
+github.com/mackerelio/mackerel-client-go v0.8.0 h1:qN3g3JVVNqh7lkXCU6xMshZq5wqUPDYvAK7UrRJyLB0=
+github.com/mackerelio/mackerel-client-go v0.8.0/go.mod h1:/FVnUK7nsg/MEBpIVOCZLYzdIwY5mg/SyAlXDnxVcAI=
 github.com/mattn/go-colorable v0.1.1/go.mod h1:FuOcm+DKB9mbwrcAfNl7/TZVBZ6rcnceauSikq3lYCQ=
 github.com/mattn/go-encoding v0.0.2 h1:OC1L+QXLJge9n7yIE3R5Os/UNasUeFvK3Sa4NjbDi6c=
 github.com/mattn/go-encoding v0.0.2/go.mod h1:WUNsdPQLK4JYRzkn8IAdmYKFYGGJ4/9YPxdPoMumPgY=