Update minimum Clojure version to 1.9

Author: weavejester

project.clj

@@ -3,20 +3,17 @@
   :url "https://github.com/ring-clojure/ring-mock"
   :license {:name "The MIT License"
             :url "http://opensource.org/licenses/MIT"}
-  :dependencies [[org.clojure/clojure "1.7.0"]
+  :dependencies [[org.clojure/clojure "1.9.0"]
                  [cheshire "6.0.0"]
                  [ring/ring-codec "1.3.0"]]
   :plugins [[lein-codox "0.10.8"]]
   :codox
   {:project     {:name "Ring-Mock"}
    :output-path "codox"
    :source-uri  "https://github.com/ring-clojure/ring-mock/blob/{version}/{filepath}#L{line}"}
-  :aliases {"test-all" ["with-profile" "default:+1.8:+1.9:+1.10:+1.11:+1.12" "test"]}
+  :aliases {"test-all" ["with-profile" "default:+1.10:+1.11:+1.12" "test"]}
   :profiles
-  {:1.8  {:dependencies [[org.clojure/clojure "1.8.0"]]}
-   :1.9  {:dependencies [[org.clojure/clojure "1.9.0"]
-                         [ring/ring-spec "0.0.4"]]}
-   :1.10 {:dependencies [[org.clojure/clojure "1.10.0"]
+  {:1.10 {:dependencies [[org.clojure/clojure "1.10.0"]
                          [ring/ring-spec "0.0.4"]]}
    :1.11 {:dependencies [[org.clojure/clojure "1.11.0"]
                          [ring/ring-spec "0.0.4"]]}