Remove old experimental includes

We are now using c++17 so we no longer need experimental optional and
any. We can use the standard any and optional now.

Change-Id: I88fcb4258c69ac5ad9766e2c65463c52a3b7f05f
Signed-off-by: William A. Kennington III <wak@google.com>
diff --git a/mainloop.hpp b/mainloop.hpp
index 77419e5..9c50c78 100644
--- a/mainloop.hpp
+++ b/mainloop.hpp
@@ -8,9 +8,9 @@
 #include "timer.hpp"
 #include "types.hpp"
 
-#include <experimental/any>
-#include <experimental/optional>
+#include <any>
 #include <memory>
+#include <optional>
 #include <sdbusplus/server.hpp>
 #include <string>
 #include <vector>
@@ -21,8 +21,6 @@
 static constexpr auto sensorLabel = 1;
 using SensorIdentifiers = std::tuple<std::string, std::string>;
 
-namespace optional_ns = std::experimental;
-
 /** @class MainLoop
  *  @brief hwmon-readd main application loop.
  */
@@ -135,6 +133,6 @@
      * @return - Optional
      *     Object state data on success, nothing on failure
      */
-    optional_ns::optional<ObjectStateData>
+    std::optional<ObjectStateData>
         getObject(SensorSet::container_t::const_reference sensor);
 };