add minimum requirements configuration to azure conda linux (#1006)

* add suffix to azure conda linux

* whatsnew

Author: wholmgren

ci/azure/conda_linux.yml

@@ -10,6 +10,9 @@ jobs:
     matrix:
       Python35:
         python.version: '35'
+      Python35-min:
+        python.version: '35'
+        suffix: '-min'
       Python36:
         python.version: '36'
         coverage: true
@@ -21,7 +24,7 @@ jobs:
   steps:
   - bash: echo "##vso[task.prependpath]/usr/share/miniconda/bin"
     displayName: Add conda to PATH
-  - script: conda env create --quiet --file ci/requirements-py$(python.version).yml
+  - script: conda env create --quiet --file ci/requirements-py$(python.version)$(suffix).yml
     displayName: Create Anaconda environment
   - script: |
       source activate test_env

docs/sphinx/source/whatsnew/v0.8.0.rst

@@ -35,6 +35,8 @@ Testing
   applied to functions that require args or kwargs. (:pull:`973`)
 * Test added for :py:class:`pvlib.modelchain.ModelChain` to confirm ValueError when
   ``ac_model`` is an invalid string. (:pull:`886`)
+* Add minimum requirements configuration to Azure Pipelines build.
+  (:pull:`1006`)
 
 Documentation
 ~~~~~~~~~~~~~
@@ -63,3 +65,4 @@ Contributors
 * Mark Mikofski (:ghuser:`mikofski`)
 * Joshua S. Stein (:ghuser:`jsstein`)
 * Marc A. Anoma (:ghuser:`anomam`)
+* Will Holmgren (:ghuser:`wholmgren`)