build(deps): bump github.com/prometheus/client_golang (#85)

Bumps [github.com/prometheus/client_golang](https://github.com/prometheus/client_golang) from 1.2.0 to 1.2.1.
- [Release notes](https://github.com/prometheus/client_golang/releases)
- [Changelog](https://github.com/prometheus/client_golang/blob/master/CHANGELOG.md)
- [Commits](https://github.com/prometheus/client_golang/compare/v1.2.0...v1.2.1)

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

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/kr/pretty v0.1.0 // indirect
 	github.com/pkg/errors v0.8.1 // indirect
 	github.com/povilasv/prommod v0.0.12
-	github.com/prometheus/client_golang v1.2.0
+	github.com/prometheus/client_golang v1.2.1
 	github.com/russross/blackfriday v2.0.0+incompatible
 	github.com/sebest/xff v0.0.0-20160910043805-6c115e0ffa35
 	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect

go.sum

@@ -56,6 +56,8 @@ github.com/prometheus/client_golang v1.0.0 h1:vrDKnkGzuGvhNAL56c7DBz29ZL+KxnoR0x
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
 github.com/prometheus/client_golang v1.2.0 h1:g4yo/h/me4ZL9o0SVHNRdS2jn5SY8GDmMgkhQ8Mz70s=
 github.com/prometheus/client_golang v1.2.0/go.mod h1:XMU6Z2MjaRKVu/dC1qupJI9SiNkDYzz3xecMgSW/F+U=
+github.com/prometheus/client_golang v1.2.1 h1:JnMpQc6ppsNgw9QPAGF6Dod479itz7lvlsMzzNayLOI=
+github.com/prometheus/client_golang v1.2.1/go.mod h1:XMU6Z2MjaRKVu/dC1qupJI9SiNkDYzz3xecMgSW/F+U=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=