Refactor project structure: update Java version, remove MQ7 files, and add BMP280 support

hardware/lib/BMP280.c

@@ -0,0 +1,17 @@
+#include "BMP280.h"
+
+
+void BMP280_Init()
+{
+
+}
+
+uint8_t BMP280_DataReady()
+{
+
+}
+
+void BMP280_Read(float &temperature, float &humidity, float &pressure, float &altitude)
+{
+
+}