Use plain pytest for Python 2.7

Author: tswast

.travis.yml

@@ -4,7 +4,7 @@ matrix:
   include:
   - os: linux
     python: 2.7
-    env: PYTHON=2.7 PANDAS=0.19.2 COVERAGE='false' LINT='true'
+    env: PYTHON=2.7 PANDAS=0.19.2 COVERAGE='false' LINT='false'
   - os: linux
     python: 3.5
     env: PYTHON=3.5 PANDAS=0.18.1 COVERAGE='true' LINT='false'
@@ -49,7 +49,11 @@ install:
     fi
 
 script:
-  - if [[ $PYTHON == '2.7' ]]; then nox -s test ; fi
+  - if [[ $PYTHON == '2.7' ]]; then
+      pip install -r ci/requirements-2.7-0.19.2.pip ;
+      pip install -e . ;
+      pytest tests/unit ;
+    fi
   - if [[ $PYTHON == '3.5' ]]; then nox -s test_earliest_deps ; fi
   - if [[ $PYTHON == '3.6' ]] && [[ "$PANDAS" == "MASTER" ]]; then nox -s test_latest_deps ; fi
   - REQ="ci/requirements-${PYTHON}-${PANDAS}" ;