Add prototype of pipeline api using connect

This includes refactoring of the http listener to use
a custom mux.

go.sum

@@ -241,6 +241,8 @@ github.com/boombuler/barcode v1.0.1-0.20190219062509-6c824513bacc/go.mod h1:paBW
 github.com/boombuler/barcode v1.0.1/go.mod h1:paBWMcWSl3LHKBqUq+rly7CNSldXjb2rDl3JlRe0mD8=
 github.com/bradfitz/gomemcache v0.0.0-20190329173943-551aad21a668/go.mod h1:H0wQNHz2YrLsuXOZozoeDmnHXkNCRmMW0gwFWDfEZDA=
 github.com/bradfitz/gomemcache v0.0.0-20190913173617-a41fca850d0b/go.mod h1:H0wQNHz2YrLsuXOZozoeDmnHXkNCRmMW0gwFWDfEZDA=
+github.com/bufbuild/connect-go v1.4.1 h1:6usL3JGjKhxQpvDlizP7u8VfjAr1JkckcAUbrdcbgNY=
+github.com/bufbuild/connect-go v1.4.1/go.mod h1:9iNvh/NOsfhNBUH5CtvXeVUskQO1xsrEviH7ZArwZ3I=
 github.com/buildkite/terminal-to-html/v3 v3.7.0/go.mod h1:g0ME1XqbkBSgXR9YmlIHcJIjzaMyWW+HbsG0rPb5puo=
 github.com/bwesterb/go-ristretto v1.2.0/go.mod h1:fUIoIZaG73pV5biE2Blr2xEzDoMj7NFEuV9ekS419A0=
 github.com/bwesterb/go-ristretto v1.2.1/go.mod h1:fUIoIZaG73pV5biE2Blr2xEzDoMj7NFEuV9ekS419A0=
@@ -611,8 +613,8 @@ github.com/google/go-cmp v0.5.4/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.5/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8/DtOE=
-github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
 github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
 github.com/google/go-github/v28 v28.1.1/go.mod h1:bsqJWQX05omyWVmc00nEUql9mhQyv38lDZ8kPZcQVoM=
 github.com/google/go-github/v45 v45.2.0/go.mod h1:FObaZJEDSTa/WGCzZ2Z3eoCDXWJKMenWWTrd8jrta28=
 github.com/google/go-licenses v0.0.0-20210329231322-ce1d9163b77d/go.mod h1:+TYOmkVoJOpwnS0wfdsJCV9CoD5nJYsHoFk/0CrTK4M=