add server plugins feature and add zookeeper/etcd/consul registries

errors/error.go

@@ -0,0 +1,18 @@
+package errors
+
+import "fmt"
+
+// MultiError holds multiple errors
+type MultiError struct {
+	Errors []error
+}
+
+// Error returns the message of the actual error
+func (e *MultiError) Error() string {
+	return fmt.Sprintf("%v", e.Errors)
+}
+
+// NewMultiError creates and returns an Error with error splice
+func NewMultiError(errors []error) *MultiError {
+	return &MultiError{Errors: errors}
+}