Build/test against modern CLJS versions

[mrrodriguez]

I noticed that the current version of ClojureScript that Clara is using for building and testing is by CLJS standards fairly ancient now.

I understand the desire to support older versions of CLJ and CLJS. However, the risk here is that we are not testing against newer versions. Also, there have been some possibly fairly significant new features in CLJS since this version [org.clojure/clojurescript "1.7.170"].

It is worth considering upgrading it or at least making some more build profiles to test different versions of things. A similar argument could be made about the CLJ version dependency, however, there are less new versions of CLJ in comparison to CLJS - and that'd be a separate issue.

[mrrodriguez]

I have noticed that #358 sort of addresses some of this issue. I'm not sure a single profile is what I had in mind, but it's a start.