readme: fix typo
readme: fix typo

PR-URL: #85 
Reviewed-By: Richard Chamberlain <41443d01ad8fa0faa0a108e0b84d83e58b74739b@uk.ibm.com>
Reviewed-By: Fedor Indutny <e39d94bae70283f13d24c278e04952d6dad9384b@indutny.com>
hhellyer/llnode,rnchamberlain/llnode,rnchamberlain/llnode,hhellyer/llnode,hhellyer/llnode,rnchamberlain/llnode,hhellyer/llnode,rnchamberlain/llnode