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

hardware/include/BMP280.h

@@ -0,0 +1,8 @@
+#include <Wire.h>
+#include <BMP280_DEV.h>
+
+#define I2C_BMP280_ADDRESS 0x76
+
+void BMP280_Init();
+uint8_t BMP280_DataReady();
+void BMP280_Read();