CI: Enable doctests

Author: effigies

.azure-pipelines/windows.yml

@@ -114,7 +114,7 @@ jobs:
         mkdir for_testing
         cd for_testing
         cp ../.coveragerc .
-        pytest --cov nibabel -v --pyargs nibabel
+        pytest --doctest-modules --cov nibabel -v --pyargs nibabel
       displayName: 'Pytest tests'
       condition: and(succeeded(), eq(variables['CHECK_TYPE'], 'test'))
     - script: |

.travis.yml

@@ -206,7 +206,7 @@ script:
           mkdir for_testing
           cd for_testing
           cp ../.coveragerc .
-          pytest --cov nibabel -v --pyargs nibabel
+          pytest --doctest-modules --cov nibabel -v --pyargs nibabel
       else
           false
       fi