setup-rubygems.sh in sendgrid_webapi-0.1.0

- old
+ new

@@ -1,5 +1,5 @@
 #!/bin/sh
 
-mkdir ~/.gem
+mkdir -p ~/.gem
 echo -e "---\r\n:rubygems_api_key: $RUBYGEMS_API_KEY" > ~/.gem/credentials
 chmod 0600 /home/circleci/.gem/credentials