message: Fixed a couple sensor tests which were failing
  due to recent merge
diff: @@ -227,6 +227,7 @@ TEST(SensorTests, TidalVolume) {
  // init value = time between sensors' init and first measure * first flow / 2
  TVIntegrator tidal_volume;
  Sensors sensors;
  + sensors.Calibrate();
  for (uint i = 0; i < sampling_time.size(); i++) {
  Pressure p_in = pressure_in[i];
  @@ -255,6 +256,7 @@ TEST(SensorTests, Calibration) {
  MPXV5004_PressureToVoltage(init_outflow_delta));
  Sensors sensors;
  + sensors.Calibrate();
  // get the sensor readings for the init signals, expect 0
  SensorReadings readings = sensors.GetSensorReadings();
  