Bump github.com/stretchr/testify from 1.6.1 to 1.7.0

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.6.1 to 1.7.0.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](stretchr/testify@v1.6.1...v1.7.0)

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

go.mod

@@ -2,4 +2,4 @@ module github.com/gookit/event
 
 go 1.12
 
-require github.com/stretchr/testify v1.6.1
+require github.com/stretchr/testify v1.7.0