Add provider registry support.
diff --git a/errors.go b/errors.go
new file mode 100644
index 0000000..53397e1
--- /dev/null
+++ b/errors.go
@@ -0,0 +1,9 @@
+package gophercloud
+
+import (
+	"fmt"
+)
+
+var ErrNotImplemented = fmt.Errorf("Not implemented")
+var ErrProvider = fmt.Errorf("Missing or incorrect provider")
+var ErrCredentials = fmt.Errorf("Missing or incomplete credentials")