build: update go modules

- declare go version 1.13
- update vendored sources
- tidy go.mod

PR: #21

go.mod

@@ -12,7 +12,10 @@ require (
 	github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e // indirect
 	github.com/prometheus/procfs v0.0.0-20180920065004-418d78d0b9a7 // indirect
 	github.com/rs/zerolog v1.9.1
+	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e // indirect
 	golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
 	gopkg.in/yaml.v2 v2.2.1 // indirect
 )
+
+go 1.13

go.sum

@@ -20,8 +20,11 @@ github.com/prometheus/procfs v0.0.0-20180920065004-418d78d0b9a7 h1:NgR6WN8nQ4SmF
 github.com/prometheus/procfs v0.0.0-20180920065004-418d78d0b9a7/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/rs/zerolog v1.9.1 h1:AjV/SFRF0+gEa6rSjkh0Eji/DnkrJKVpPho6SW5g4mU=
 github.com/rs/zerolog v1.9.1/go.mod h1:YbFCdg8HfsridGWAh22vktObvhZbQsZXe4/zB0OKkWU=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e h1:o3PsSEY8E4eXWkXrIP9YJALUkVZqzHJT5DOasTyn8Vs=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/natefinch/lumberjack.v2 v2.0.0 h1:1Lc07Kr7qY4U2YPouBjpCLxpiyxIVoxqXgkXLknAOE8=
 gopkg.in/natefinch/lumberjack.v2 v2.0.0/go.mod h1:l0ndWWf7gzL7RNwBG7wST/UCcT4T24xpD6X8LsfU/+k=

vendor/modules.txt

@@ -15,13 +15,13 @@ github.com/prometheus/client_golang/prometheus/promhttp
 github.com/prometheus/client_model/go
 # github.com/prometheus/common v0.0.0-20180801064454-c7de2306084e
 github.com/prometheus/common/expfmt
-github.com/prometheus/common/model
 github.com/prometheus/common/internal/bitbucket.org/ww/goautoneg
+github.com/prometheus/common/model
 # github.com/prometheus/procfs v0.0.0-20180920065004-418d78d0b9a7
 github.com/prometheus/procfs
+github.com/prometheus/procfs/internal/util
 github.com/prometheus/procfs/nfs
 github.com/prometheus/procfs/xfs
-github.com/prometheus/procfs/internal/util
 # github.com/rs/zerolog v1.9.1
 github.com/rs/zerolog
 github.com/rs/zerolog/internal/cbor