Allow to specific custom version for path repositories

[vtsykun]

Purpose

As developer I want to ignore guess version for path repository and specific it in main composer.json. For example I develop new feature for composer installable package (local branch name "feature/example") and want to test it on my project. But I can not install this package without modification main composer.json or composer.json in this package.
These changes allow to ignore guess version.

Second example
I want to install for testing "symfony/symfony": "dev-master", but some package requires a specific symfony version.

Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - incenteev/composer-parameter-handler v2.1.2 requires symfony/yaml ~2.3|~3.0 -> satisfiable by symfony/symfony[v3.3.5], s

But I use this approach, I can circumvent these requirements and install master from path

Usage

    "repositories": [
        {
            "type": "path",
            "url": "package/*",
            "options": {
                "versions": {"symfony/symfony": "3.3.6"}
            }
        }
    ]

[Seldaek]

The way to do this IMO is to use aliases so you can require "symfony/symfony": "dev-master as 3.3.1000" for example and keep the path repo untouched.