Move all pretty printers to pretty_printers.hpp

Next step is to get rid of std extensions.

Change-Id: Ib24c66521e6e7899cf2dae159d01e11f13622631
diff --git a/tests/leaf_editing.cpp b/tests/leaf_editing.cpp
index ca5c8d6..76e26d3 100644
--- a/tests/leaf_editing.cpp
+++ b/tests/leaf_editing.cpp
@@ -11,14 +11,10 @@
 #include "ast_commands.hpp"
 #include "leaf_data_helpers.hpp"
 #include "parser.hpp"
+#include "pretty_printers.hpp"
 #include "static_schema.hpp"
 #include "utils.hpp"
 
-std::ostream& operator<<(std::ostream& s, const set_ cmd)
-{
-    return s << "Command SET {path: " << pathToSchemaString(cmd.m_path, Prefixes::Always) << ", type " << boost::core::demangle(cmd.m_data.type().name()) << ", data: " << leafDataToString(cmd.m_data) << "}";
-}
-
 TEST_CASE("leaf editing")
 {
     auto schema = std::make_shared<StaticSchema>();