refactor: remove utils pkg

BREAKING CHANGE: utils package has been removed in favor of specific new
packages (http, crypto, strings)

pkg/http/marshal.go

@@ -0,0 +1,33 @@
+package http
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func MarshalJSON(w http.ResponseWriter, i interface{}) {
+	MarshalJSONWithStatus(w, i, http.StatusOK)
+}
+
+func MarshalJSONWithStatus(w http.ResponseWriter, i interface{}, status int) {
+	w.Header().Set("content-type", "application/json")
+	w.WriteHeader(status)
+	err := json.NewEncoder(w).Encode(i)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}
+
+func ConcatenateJSON(first, second []byte) ([]byte, error) {
+	if !bytes.HasSuffix(first, []byte{'}'}) {
+		return nil, fmt.Errorf("jws: invalid JSON %s", first)
+	}
+	if !bytes.HasPrefix(second, []byte{'{'}) {
+		return nil, fmt.Errorf("jws: invalid JSON %s", second)
+	}
+	first[len(first)-1] = ','
+	first = append(first, second[1:]...)
+	return first, nil
+}