Use shellcheck on yourself

Fixing shellcheck warnings on shell scripts in this repo.

nextnumber

@@ -8,6 +8,6 @@ fi
 
 for i in 1 2
 do
-  last=$(grep -hv "^prop" ./**/*.hs | grep -Ewo "$i[0-9]{3}" | sort -n | tail -n 1)
+  last=$(grep -hv "^prop" ./**/*.hs | grep -Ewo "${i}[0-9]{3}" | sort -n | tail -n 1)
   echo "Next ${i}xxx: $((last+1))"
 done