[conda] Revert BOB_NOSE_FAST hack in favour of using environment variables supported by nosetests

conda/meta.yaml

@@ -62,11 +62,7 @@ test:
     - bob tf train --help
     - bob tf train-and-evaluate --help
     - bob tf trim --help
-    {% if environ.get('BOB_NOSE_FAST') %}
-    - nosetests --with-coverage --cover-package={{ name }} -sv {{ name }} -a '!slow'
-    {% else %}
     - nosetests --with-coverage --cover-package={{ name }} -sv {{ name }}
-    {% endif %}
     - sphinx-build -aEW {{ project_dir }}/doc {{ project_dir }}/sphinx
     - sphinx-build -aEb doctest {{ project_dir }}/doc sphinx
     - conda inspect linkages -p $PREFIX {{ name }}  # [not win]