Remove wrongly copy-pasted ert-runner -l argument.

Author: proofit404

.travis.yml

@@ -23,4 +23,4 @@ install:
   - evm install $EVM_EMACS --use
   - cask install
 script:
-  - cask exec ert-runner -l test/interpreters/$INTERPRETER.el
+  - cask exec ert-runner