Cannot install due to security-advisory check

[sirbrillig]

When I try to run composer install on a package that requires this package, I get the following error:

    - sirbrillig/phpcs-variable-analysis dev-master requires roave/security-advisories dev-master -> satisfiable by roave/security-advisories[dev-master] but these conflict with your requirements or minimum-stability.

This was introduced in #5

To reproduce, have a composer.json with these requirements:

    "require-dev": {
        "sirbrillig/phpcs-variable-analysis": "dev-master"
    }

[sirbrillig]

ping @GaryJones because I'm not clear why this is showing up.

[GaryJones]

Either this project or your consuming project, will likely need:

    "minimum-stability": "dev",
    "prefer-stable": true,

in the composer.json.

[sirbrillig]

Thanks for figuring that out. TIL. From testing it looks like it's necessary to add it to both this project and the consuming project. I'll add a note in the README, since those fields are not automatically added by composer init and so I wouldn't be surprised if other people run into this as well.

[sirbrillig]

At the moment, I find requiring the minimum-stability field is too much of a burden on developers who just want to include this standard, so I've removed the roave/security-advisories package for now.