Added a random error checking function

Not actually sure I'll use it?

components/dht22/dht22.h

@@ -11,6 +11,7 @@ typedef enum {
 typedef uint16_t deci_percent;
 typedef int16_t  deci_degrees_c;
 
+void dht22_handle_error();
 deci_percent dht22_relative_humidity();
 deci_degrees_c dht22_temperature();
 dht22_error dht22_read();