Add <cassert> header include

This fixes some Linux build failures.

2016/puzzle-10-02.cc

@@ -3,6 +3,7 @@
 //
 
 #include <algorithm>
+#include <cassert>
 #include <iostream>
 #include <regex>
 #include <string>
@@ -127,4 +128,4 @@ auto main() -> int
   }
 
   std::cout << "Result: " << outputs[0] * outputs[1] * outputs[2] << '\n';
-}
+}