refactored displays

FlippR-Driver/include/output/items/SevenDigitDisplay.h

@@ -7,7 +7,7 @@
 
 #include "Display.h"
 
-#include <array>
+#include <string>
 
 namespace flippR_driver
 {
@@ -19,7 +19,9 @@ namespace items
 class SevenDigitDisplay : public Display
 {
 public:
-  virtual void write_content(std::array<char, 7> content) = 0;
+  virtual ~SevenDigitDisplay() = default;
+
+  virtual void write_content(std::string content) = 0;
 };
 
 }