beer_song: initial commit

cpp/beer-song/beer_song.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#define EXERCISM_RUN_ALL_TESTS
+
+#include <string>
+
+namespace beer {
+
+std::string verse(int index);
+std::string sing(int from_index, int to_index = 0);
+
+}