My quick and dirty way to solve was,
just rename the structure from sensor_t to Adafruit_sensor_t in all related files.
Adafruit_BME280.cpp, Adafruit_BME280.h, Adafruit_Sensor.cpp and Adafruit_Sensor.h
and include all files into your project.
Then change all includes to the two header files to locally (e.g. change
#include <Adafruit_Sensor.h>
to
#include "Adafruit_Sensor.h"
)
That's it