Fix the upstream-dev pandas build failure (#4138)

* use the scipy-wheels-nightly repository for numpy, scipy and pandas

* update the repository url

* avoid installing over the conda packages

* use the repository as a package index

* run the uninstall with -y

* use the correct url for the scipy-wheels-nightly repository

ci/azure/install.yml

@@ -12,14 +12,32 @@ steps:
 
 - bash: |
     source activate xarray-tests
+    conda uninstall -y --force \
+        numpy \
+        scipy \
+        pandas \
+        matplotlib \
+        dask \
+        distributed \
+        zarr \
+        cftime \
+        rasterio \
+        pint \
+        bottleneck
     python -m pip install \
-        -f https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf2.rackcdn.com \
+        -i https://pypi.anaconda.org/scipy-wheels-nightly/simple \
         --no-deps \
         --pre \
         --upgrade \
-        matplotlib \
         numpy \
-        scipy
+        scipy \
+        pandas
+    python -m pip install \
+        -f https://7933911d6844c6c53a7d-47bd50c35cd79bd838daf386af554a83.ssl.cf2.rackcdn.com \
+        --no-deps \
+        --pre \
+        --upgrade \
+        matplotlib
     python -m pip install \
         --no-deps \
         --upgrade \
@@ -29,8 +47,7 @@ steps:
         git+https://github.com/Unidata/cftime \
         git+https://github.com/mapbox/rasterio \
         git+https://github.com/hgrecco/pint \
-        git+https://github.com/pydata/bottleneck \
-        git+https://github.com/pandas-dev/pandas
+        git+https://github.com/pydata/bottleneck
   condition: eq(variables['UPSTREAM_DEV'], 'true')
   displayName: Install upstream dev dependencies