Add callback support to triggerable actions

Change-Id: Icc27fbe9403eda418f41e12c76af7f3216f4b72a
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/bmc/skip_action.hpp b/bmc/skip_action.hpp
index 65fcfc8..4fc9462 100644
--- a/bmc/skip_action.hpp
+++ b/bmc/skip_action.hpp
@@ -23,16 +23,9 @@
     SkipAction(SkipAction&&) = default;
     SkipAction& operator=(SkipAction&&) = default;
 
-    bool trigger() override
-    {
-        return true;
-    }
-    void abort() override
-    {}
-    ActionStatus status() override
-    {
-        return ActionStatus::success;
-    }
+    bool trigger() override;
+    void abort() override;
+    ActionStatus status() override;
 };
 
 } // namespace ipmi_flash