Update package.json

The dependency file is incorrect, since propagate requires node 0.8.1

npm ERR! Unsupported
npm ERR! Not compatible with your version of node/npm: propagate@0.2.2
npm ERR! Required: ["node >= 0.8.1"]
npm ERR! Actual:   {"npm":"1.1.24","node":"0.6.19"}
npm ERR! 
npm ERR! System Darwin 12.3.0
npm ERR! command "node" "/usr/local/bin/npm" "install"
npm ERR! cwd /Users/vrmink/paddle/git/active-sender
npm ERR! node -v v0.6.19
npm ERR! npm -v 1.1.24
npm ERR! code ENOTSUP
npm ERR! message Unsupported
npm ERR! errno {}