Removed the `scripts` field on composer config

The `scripts` field is useless on a library package.

From the composer documentation v1.0:

> Note: Only scripts defined in the root package's `composer.json` are
> executed. If a dependency of the root package specifies its own scripts,
> Composer does not execute those additional scripts.
Merge pull request #94 from alquerci/rm/composer-script-entry

Removed the `scripts` field on composer config