Version in composer should be <1.4

[Tsht]

As it's <=1.3, it won't work with 1.3.4 for instance. I think it's not meant to be this way.

Example :

Problem 1

• deralex/yaml-config-service-provider 1.0.x-dev requires silex/silex >=1.0 <=1.3 -> satisfiable by silex/silex[v1.3.0].
• deralex/yaml-config-service-provider 1.0.x-dev requires silex/silex >=1.0 <=1.3 -> satisfiable by silex/silex[v1.3.0].
• Conclusion: don't install silex/silex v1.3.0
• Installation request for deralex/yaml-config-service-provider 1.0.x-dev -> satisfiable by deralex/yaml-config-service-provider[1.0.x-dev].

with "silex/silex" : "^1.3"

[SebastienTainon]

:+1: It works for Silex 1.3