Fix npm error when booting hubot

Npm raised an error when executing README.md's install instraction.
```
$ hubot -a kandan
npm ERR! Darwin 14.0.0
npm ERR! argv "node" "/usr/local/bin/npm" "install"
npm ERR! node v0.10.33
npm ERR! npm  v2.1.6
npm ERR! code ETARGET

npm ERR! notarget No compatible version found: hubot-kandan@'>=1.0.0 <1.1.0'
npm ERR! notarget Valid install targets:
npm ERR! notarget ["0.9.0","0.9.1","0.9.2","0.9.3","0.9.4","0.9.5","0.9.6"]
npm ERR! notarget
npm ERR! notarget This is most likely not a problem with npm itself.
npm ERR! notarget In most cases you or one of your dependencies are requesting
npm ERR! notarget a package version that doesn't exist.

npm ERR! Please include the following file with any support request:
npm ERR!     /Users/yuuki/docker/hubot/npm-debug.log
bin/hubot: line 6: /Users/yuuki/docker/hubot/node_modules/.bin/hubot: No such file or 
```
It is caused by validation of semantic versioning.