build: update dependencies

[xballoy]

Update Echo from 4.6.1 to 4.9.1

[jmaitrehenry]

If the minimal version of go is 1.16, it should be 1.16 here too

[xballoy]

I was inspired by what Echo does. They put go 1.17 (see labstack/echo#2049) to benefit new from new Go features but still test up to 1.16 (https://github.com/labstack/echo/blob/master/.github/workflows/echo.yml#L31).

However I'm still trying to figure out why the golangcli-lint fails (maybe this golangci/golangci-lint#2649 but still need to run some tests to be sure).

[xballoy]

In the end I used go 1.17 here and in the CI. I never managed to run the CI with go 1.16, golangcli-lint always fails with this version and the dependency bump.

go 1.17 is the same version than echo 4.9.1 so I think we're good here.