Bump org.clojure:clojure from 1.7.0 to 1.9.0

Bumps [org.clojure:clojure](https://github.com/clojure/clojure) from 1.7.0 to 1.9.0.
- [Changelog](https://github.com/clojure/clojure/blob/master/changes.md)
- [Commits](clojure/clojure@clojure-1.7.0...clojure-1.9.0)

---
updated-dependencies:
- dependency-name: org.clojure:clojure
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -31,7 +31,7 @@
 
   <properties>
     <clojure.warnOnReflection>true</clojure.warnOnReflection>
-    <clojure.version>1.7.0</clojure.version>
+    <clojure.version>1.9.0</clojure.version>
   </properties>
 
   <developers>