Suppress version from composer

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There are two ways to manage version numbering. The easiest is to just omit the version field from the composer.json file. If it is missing, the version name will be parsed from the tag and branch names. The other way which offers you a bit more flexibility is to define it yourself, but that means you should update the version field in the composer.json file before creating a tag, otherwise the tag will be considered broken and not imported. If you think you're likely to forget, you probably should use the first method.