Loop once per 5 seconds.

Clean up CRC8 functions (style, no caps).

src/main.c

@@ -90,7 +90,7 @@ int main() {
   for (;;) {
     do_sht31(sht31);
     do_si7021(si7021);
-    sleep(1);
+    sleep(5);
   }
 
   mgos_sht31_destroy(&sht31);