Use almost minimal dependencies in Python 2 build on CircleCI (scikit-learn#10627)

Author: lesteve

.circleci/config.yml

@@ -38,11 +38,15 @@ jobs:
       # PYTHON_VERSION environment variable.
       - image: circleci/python:3.6.1
     environment:
+      # Test examples run with minimal dependencies
       - MINICONDA_PATH: ~/miniconda
       - CONDA_ENV_NAME: testenv
       - PYTHON_VERSION: 2
-      - MATPLOTLIB_VERSION: "1.3"
-      - SCIKIT_IMAGE_VERSION: "0.9.3"
+      - NUMPY_VERSION: 1.8.2
+      # XXX: plot_gpc_xor.py fails with scipy 0.13.3
+      - SCIPY_VERSION: 0.14
+      - MATPLOTLIB_VERSION: 1.3
+      - SCIKIT_IMAGE_VERSION: 0.9.3
     steps:
       - checkout
       - run: ./build_tools/circle/checkout_merge_commit.sh

build_tools/circle/build_doc.sh

@@ -115,8 +115,9 @@ conda update --yes --quiet conda
 
 # Configure the conda environment and put it in the path using the
 # provided versions
-conda create -n $CONDA_ENV_NAME --yes --quiet python="${PYTHON_VERSION:-*}" numpy scipy \
-  cython pytest coverage matplotlib="${MATPLOTLIB_VERSION:-*}" sphinx=1.6.2 pillow \
+conda create -n $CONDA_ENV_NAME --yes --quiet python="${PYTHON_VERSION:-*}" \
+  numpy="${NUMPY_VERSION:-*}" scipy="${SCIPY_VERSION:-*}" cython \
+  pytest coverage matplotlib="${MATPLOTLIB_VERSION:-*}" sphinx=1.6.2 pillow \
   scikit-image="${SCIKIT_IMAGE_VERSION:-*}"
 
 source activate testenv