[conda][meta] Ensure test prefix is deleted

conda/meta.yaml

@@ -86,13 +86,14 @@ test:
     - export COVERAGE_FILE=.coverage.cmdline
     - export NOSE_WITH_COVERAGE=1
     - rm -f test.sql3 manage.py
-    - rm -r test_prefix
+    - rm -rf test_prefix
     {% if environ.get('BEAT_DOCKER_TESTS', False)  %}
     - nosetests -sv beat.cmdline
     {% else %}
     - nosetests -sv --exclude=".*test_docker.*" beat.cmdline
     {% endif %}
     - rm -f test.sql3
+    - rm -rf test_prefix
     - unset COVERAGE_FILE
 
     - coverage combine .coverage.django .coverage.cmdline