Comment made by: alexmiller
The lib is not in control of what version of Clojure it is used with - that's up to the user.
Pegging it to a lower version here (lowest supported) means that we are aware if the code starts using something newer (because of breakage). I don't know of any reason this project should not support back to Clojure 1.6.
As a separate issue, the project.clj file is helpful for dev (and cljs), but is not actually used when building or deploying the project - that's all controlled via the Maven pom.xml. So all dependency changes made in the project.clj dependencies also need to be mirrored in the pom.xml file.