Avoid the need to remove old release zips

.gitignore

@@ -1,6 +1,6 @@
 bin
 classes
 lib
+releases
 *.jar
 .DS_Store
-clojure-koans*.zip

script/deploy.sh

@@ -1,8 +1,14 @@
 #!/bin/sh
 
 git push
-zip -r clojure-koans-`date +"%Y-%m-%d_%H-%M"`.zip . -x "./.git/*"
+mkdir -p releases
+zip -r releases/clojure-koans-`date +"%Y-%m-%d_%H-%M"`.zip \
+    . \
+    -x "./.git/*" \
+    -x "releases/*"
 
 echo
-echo "Don't forget to upload the zipfile!"
-echo `ls -t clojure-koans-*.zip | head -n1`
+echo "Don't forget to upload the zipfile"
+echo "  to https://github.com/functional-koans/clojure-koans/downloads"
+echo `ls -t releases/clojure-koans-*.zip | head -n1`
+echo