remove using namespace from .h

Author: dimitre

libs/openFrameworks/utils/ofTimerFps.cpp

@@ -1,5 +1,8 @@
 #include "ofTimerFps.h"
 
+using namespace std::chrono;
+using namespace std::chrono_literals;
+
 void ofTimerFps::reset() {
    wakeTime = steady_clock::now();
 }

libs/openFrameworks/utils/ofTimerFps.h

@@ -7,9 +7,6 @@
 #include <iostream>
 #include <thread>
 
-using namespace std::chrono;
-using namespace std::chrono_literals;
-
 class ofTimerFps {
 public:
 	ofTimerFps();
@@ -19,7 +16,7 @@ class ofTimerFps {
 
 	using space = std::chrono::duration<long long, std::nano>;
 	space interval;
-	time_point<steady_clock> wakeTime;
-	time_point<steady_clock> lastWakeTime;
+	std::chrono::time_point<std::chrono::steady_clock> wakeTime;
+	std::chrono::time_point<std::chrono::steady_clock> lastWakeTime;
 
 };