fix compile error caused by missing include (#197)

* fix compile error caused by missing include

`stat_vector_3d.cpp` uses `std::runtime_error`, which is included in `stdexcept`

Author: Kurtoid

wiimote/include/wiimote/stat_vector_3d.hpp

@@ -29,7 +29,6 @@
 #ifndef WIIMOTE__STAT_VECTOR_3D_HPP_
 #define WIIMOTE__STAT_VECTOR_3D_HPP_
 
-
 #include <vector>
 
 // The vector of 3 values collected to generate:

wiimote/src/stat_vector_3d.cpp

@@ -32,6 +32,7 @@
 #include <cmath>
 #include <functional>
 #include <numeric>
+#include <stdexcept>
 
 StatVector3d::StatVector3d() {count_ = 0;}