Update Vendors (#250)

update go min version

Update Vendors:
 * code.gitea.io/gitea-vet v0.2.0 -> v0.2.1
 * code.gitea.io/sdk/gitea v0.13.0 -> v0.13.1
 * github.com/AlecAivazis/survey v2.1.1 -> v2.2.2
 * github.com/adrg/xdg v0.2.1 -> v0.2.2
 * github.com/araddon/dateparse d820a6159ab1 -> 8aadafed4dc4
 * github.com/go-git/go-git v5.1.0 -> v5.2.0
 * github.com/muesli/termenv v0.7.2 -> v0.7.4
 * github.com/stretchr/testify v1.5.1 -> v1.6.1
 * github.com/urfave/cli v2.2.0 -> v2.3.0

Co-authored-by: 6543 <6543@obermui.de>
Reviewed-on: https://gitea.com/gitea/tea/pulls/250
Reviewed-by: Andrew Thornton <art27@cantab.net>
Reviewed-by: mrsdizzie <info@mrsdizzie.com>
Co-Authored-By: 6543 <6543@noreply.gitea.io>
Co-Committed-By: 6543 <6543@noreply.gitea.io>

vendor/github.com/aymerick/douceur/css/stylesheet.go

@@ -0,0 +1,25 @@
+package css
+
+// Stylesheet represents a parsed stylesheet
+type Stylesheet struct {
+	Rules []*Rule
+}
+
+// NewStylesheet instanciate a new Stylesheet
+func NewStylesheet() *Stylesheet {
+	return &Stylesheet{}
+}
+
+// Returns string representation of the Stylesheet
+func (sheet *Stylesheet) String() string {
+	result := ""
+
+	for _, rule := range sheet.Rules {
+		if result != "" {
+			result += "\n"
+		}
+		result += rule.String()
+	}
+
+	return result
+}