stop installing manager header

Stop installing the manager header as it is no longer meant to be
exported, but rather used only internally within this repository.

Change-Id: I2ab21a31fd745e1b3e36fc39ffea5e26d373ff51
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/ipmi.hpp b/ipmi.hpp
index a09d347..93bc953 100644
--- a/ipmi.hpp
+++ b/ipmi.hpp
@@ -1,8 +1,9 @@
 #pragma once
 
+#include "manager.hpp"
+
 #include <host-ipmid/ipmid-api.h>
 
-#include <blobs-ipmid/manager.hpp>
 #include <string>
 
 namespace blobs