Set default test runner function for :test alias

This commit sets in deps.edn the default main function to be run when
using the :test alias, making the command to run tests shorter, and
documents this shorter command in README.md.

Signed-off-by: Sebastian Crane <seabass-labrax@gmx.com>

README.md

@@ -55,7 +55,7 @@ clojure -M -m system
 Running the tests is a similar process to running the main application:
 
 ```bash
-clojure -M:test -m kaocha.runner
+clojure -M:test
 ```
 
 ### Starting a development REPL

deps.edn

@@ -6,4 +6,5 @@
         clj-commons/clj-yaml {:mvn/version "0.7.107"}
         irclj/irclj {:mvn/version "0.5.0-alpha4"}}
  :aliases {:test {:extra-paths ["test"]
-                  :extra-deps {lambdaisland/kaocha {:mvn/version "1.60.972"}}}}}
+                  :extra-deps {lambdaisland/kaocha {:mvn/version "1.60.972"}}
+                  :main-opts ["-m" "kaocha.runner"]}}}