Add algorithm header include

Without algorithm header, Visual Studio complaints that std::max is not
declared and defined.
Including algorithm header resolves this issue.

RtAudio.cpp

@@ -45,6 +45,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <climits>
+#include <algorithm>
 
 // Static variable definitions.
 const unsigned int RtApi::MAX_SAMPLE_RATES = 14;