Have cooling-type use the common argument.hpp

The cooling-type application should use the common
header file for the ArgumentParser class now that one
is available.

Also fixed where a static ArgumentParser constant was
being initialized.

Change-Id: I1fb0dfe3bd0c6e0200ad7c718ef2a3def5476f3f
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/argument.hpp b/argument.hpp
index c314006..9d0ab06 100644
--- a/argument.hpp
+++ b/argument.hpp
@@ -30,7 +30,7 @@
 
         static void usage(char** argv);
 
-        static constexpr auto true_string = "true";
+        static const std::string true_string;
         static const std::string empty_string;
 
     private: