Try installing numpy first

dstansby · dstansby · commit 722eac5163d2 · 2019-10-21T21:48:57.000+01:00
diff --git a/ci/azure-pipelines-steps.yml b/ci/azure-pipelines-steps.yml
@@ -49,7 +49,7 @@ steps:
 
 - bash: |
     python -m pip install --upgrade pip
-    pip install -r requirements/testing/travis_all.txt -r requirements/testing/travis36.txt ||
+    python -m pip install -r requirements/testing/travis_all.txt -r requirements/testing/travis36.txt ||
       [[ "$PYTHON_VERSION" = 'Pre' ]]
   displayName: 'Install dependencies with pip'
 
