Stabilize composer

[ktomk]

Composer now has stable releases and supports semantic versioning. This
commit stops magento/composer from blocking stable composer requirements
as it was previously by pinning it to a specific release (1.0.0-beta1).

• Ref: Stabilize Composer magento2#4359

[cmuench]

@alankent
It would be great if you can update the requirements to the latest stable composer which is now available.
This should make the the "minimum-stability" restriction in the root composer file deprecated.

[jameshalsall]

@alankent when is this going to be merged?

[jameshalsall]

@alankent are you alive?

[tkn98]

Ref: magentocommerce.com Ticket #03188454

[maghamed]

@ktomk could you please update current PR, and once #8743 would be delivered I could process it as well.

[ktomk]

@maghamed just done, please let me know if ^1.3.2 is aiming too high for some reason, e.g. this perhaps should be aligned with the base project.

[hostep]

It looks like this is finally happening, see: 130753a

I believe this PR may get closed now, because the commit above does the same thing? @slavvka, @igrybkov, correct?

[ktomk]

A merger has not come to fruition.

The offer is forfeited.

All rights withdrawn. No commitment has been made in the past, but should it have been accepted, it is to be considered null and void in any case with the non-merger.

This is a non-legal, machine translation.

The place of jurisdiction is the place of the author.