When following the readme I ran the lein ring uberjar command which gave me the following error:

clojure.lang.Compiler$CompilerException: Syntax error macroexpanding clojure.core/fn at (clojure/core/unify.clj:83:18). #:clojure.error{:phase :macro-syntax-check, :line 83, :column 18, :source "clojure/core/unify.clj", :symbol clojure.core/fn} at clojure.lang.Compiler.checkSpecs (Compiler.java:6971)

Caused by: clojure.lang.ExceptionInfo: Call to clojure.core/fn did not conform to spec. #:clojure.spec.alpha{:problems ({:path [:fn-tail :arity-1 :params], :pred clojure.core/vector?, :val clojure.core.unify/var-unify, :via [:clojure.core.specs.alpha/params+body :clojure.core.specs.alpha/param-list :clojure.core.specs.alpha/param-list], :in [0]} {:path [:fn-tail :arity-n], :pred (clojure.core/fn [%] (clojure.core/or (clojure.core/nil? %) (clojure.core/sequential? %))), :val clojure.core.unify/var-unify, :via [:clojure.core.specs.alpha/params+body :clojure.core.specs.alpha/params+body], :in [0]}), :spec #object[clojure.spec.alpha$regex_spec_impl$reify__2509 0x2a9bc08f "clojure.spec.alpha$regex_spec_impl$reify__2509@2a9bc08f"], :value (clojure.core.unify/var-unify [G__800 G__801 G__802 G__803] (clojure.core/if-let [vb__793__auto__ (G__803 G__801)] (clojure.core.unify/garner-unifiers G__800 vb__793__auto__ G__802 G__803) (clojure.core/if-let [vexpr__794__auto__ (clojure.core/and (G__800 G__802) (G__803 G__802))] (clojure.core.unify/garner-unifiers G__800 G__801 vexpr__794__auto__ G__803) (if (clojure.core.unify/occurs? G__800 G__801 G__802 G__803) (throw (java.lang.IllegalStateException. (clojure.core/str "Cycle found in the path " G__802))) (clojure.core.unify/bind-phase G__803 G__801 G__802))))), :args (clojure.core.unify/var-unify [G__800 G__801 G__802 G__803] (clojure.core/if-let [vb__793__auto__ (G__803 G__801)] (clojure.core.unify/garner-unifiers G__800 vb__793__auto__ G__802 G__803) (clojure.core/if-let [vexpr__794__auto__ (clojure.core/and (G__800 G__802) (G__803 G__802))] (clojure.core.unify/garner-unifiers G__800 G__801 vexpr__794__auto__ G__803) (if (clojure.core.unify/occurs? G__800 G__801 G__802 G__803) (throw (java.lang.IllegalStateException. (clojure.core/str "Cycle found in the path " G__802))) (clojure.core.unify/bind-phase G__803 G__801 G__802)))))}