chore(deps): bump github.com/gin-gonic/gin from 1.7.4 to 1.7.7

Bumps [github.com/gin-gonic/gin](https://github.com/gin-gonic/gin) from 1.7.4 to 1.7.7.
- [Release notes](https://github.com/gin-gonic/gin/releases)
- [Changelog](https://github.com/gin-gonic/gin/blob/master/CHANGELOG.md)
- [Commits](gin-gonic/gin@v1.7.4...v1.7.7)

---
updated-dependencies:
- dependency-name: github.com/gin-gonic/gin
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

go.mod

@@ -3,6 +3,6 @@ module github.com/gin-contrib/cors
 go 1.13
 
 require (
-	github.com/gin-gonic/gin v1.7.4
+	github.com/gin-gonic/gin v1.7.7
 	github.com/stretchr/testify v1.7.0
 )

go.sum

@@ -3,8 +3,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
 github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
-github.com/gin-gonic/gin v1.7.4 h1:QmUZXrvJ9qZ3GfWvQ+2wnW/1ePrTEJqPKMYEU3lD/DM=
-github.com/gin-gonic/gin v1.7.4/go.mod h1:jD2toBW3GZUr5UMcdrwQA10I7RuaFOl/SGeDjXkfUtY=
+github.com/gin-gonic/gin v1.7.7 h1:3DoBmSbJbZAWqXJC3SLjAPfutPJJRN1U5pALB7EeTTs=
+github.com/gin-gonic/gin v1.7.7/go.mod h1:axIBovoeJpVj8S3BwE0uPMTeReE4+AfFtqpqaZ1qq1U=
 github.com/go-playground/assert/v2 v2.0.1 h1:MsBgLAaY856+nPRTKrp3/OZK38U/wa0CcBYNjji3q3A=
 github.com/go-playground/assert/v2 v2.0.1/go.mod h1:VDjEfimB/XKnb+ZQfWdccd7VUvScMdVu0Titje2rxJ4=
 github.com/go-playground/locales v0.13.0 h1:HyWk6mgj5qFqCT5fjGBuRArbVDfE4hi8+e8ceBS/t7Q=