Fix #1 Fix name of the bin in package.json

[ledsun]

I think #1 is caused by the difference between a file name in the bin directory and the command name in the package.json.

[akkerman]

This pull request would also fix #5 #7 #8 #9 #11

to test put the following in a package.json file in an empty directory

{
  "name": "crest_test",
  "scripts": {
    "start": "crest"
  },
  "dependencies": {
    "crest": "https://github.com/ledsun/crest.git"
  }
}

then install and start:

npm install && npm start