Bump gopkg.in/yaml.v2 from 2.2.4 to 2.2.8 (#199)

Bumps [gopkg.in/yaml.v2](https://github.com/go-yaml/yaml) from 2.2.4 to 2.2.8.
- [Release notes](https://github.com/go-yaml/yaml/releases)
- [Commits](go-yaml/yaml@v2.2.4...v2.2.8)

---
updated-dependencies:
- dependency-name: gopkg.in/yaml.v2
  dependency-type: direct:production
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -8,5 +8,5 @@ require (
 	github.com/sergi/go-diff v1.1.0 // indirect
 	github.com/stretchr/testify v1.4.0
 	golang.org/x/tools v0.1.9
-	gopkg.in/yaml.v2 v2.2.4
+	gopkg.in/yaml.v2 v2.2.8
 )

go.sum

@@ -49,5 +49,6 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
-gopkg.in/yaml.v2 v2.2.4 h1:/eiJrUcujPVeJ3xlSWaiNi3uSVmDGBK1pDHUHAnao1I=
 gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.8 h1:obN1ZagJSUGI0Ek/LBmuj4SNLPfIny3KsKFopxRdj10=
+gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=