Add the connector version to the teaser.

Besides the already in place information about the CLI version and
the core version, this PR adds also the name of the connector and 
its version from the cwd’s package.json. The result looks like this:

```
./sequelize/cli/bin/sequelize h

Sequelize [CLI: 0.2.6, ORM: 2.0.0-rc1, sqlite3: ^2.2.7]

Loaded configuration file 'config/config.json'.
Using environment 'development'.
[20:10:14] Using sequelizefile ~/Projects/sequelize/cli/lib/sequelizefile.js
[20:10:14] Starting 'help'...

Usage
  sequelize [task]

…
```

Fixes #27.
Merge pull request #45 from sequelize/feature/connector-version

Add the connector version to the teaser.