Use SemVer for Hex dependencies

[ericmj]

Hex requires pacakges to use semantic versioning. The packages amqp_client and rabbit_common uses strict version requirements on its dependencies which causes conflicts and ecosystem problems for users of those packages. Instead they should use the ~> version requirement operator that follows the rules of SemVer. ~> 1.0 will depend on any stable version >= 1.0.0 and < 2.0.0.

Current dependencies

amqp_client:
rabbit_common == 3.7.13

rabbit_common:
jsx == 2.9.0
lager == 3.6.5
ranch == 1.7.1
recon == 2.3.6

How dependencies should be declared

amqp_client:
rabbit_common ~> 3.7

rabbit_common:
jsx ~> 2.9
lager ~> 3.6
ranch ~> 1.7
recon ~> 2.3