Dependencies are pinned

[dvzrv]

Hi! I package this project for Arch Linux.

For system packaging it is problematic to pin dependencies the way it is done in this project:

django-compressor/setup.py

Lines 167 to 168 in 939499e

	"rcssmin == 1.1.1",
	"rjsmin == 1.2.1",

Downstream we have to remove the specific version pinning, as we are a floating target where only one version of a given library can exist. However, even for user installs of this library it is problematic, as installing django-compressor requires a specific version of these libraries and a different library may require them to be less strict.

[bcail]

@diox Would it be an option to require rcssmin >= 1.1.1 and rjsmin >= 1.2.1? Or to drop the versions completely from setup.py? If so, I could submit a PR.