[INFRA] Add tests min requirements with Matplotlib (#3144)

* Add tests min req with matplotlib

* remove useless variable

* [circle full] update README

.github/workflows/testing.yml

@@ -55,6 +55,36 @@ jobs:
         if: success()
         name: 'Upload coverage to CodeCov'
 
+  min_requirements_matplotlib:
+    needs: check_skip
+    if: ${{ needs.check_skip.outputs.skip == 'false' }}
+    runs-on: "ubuntu-latest"
+    name: Python 3.6, minimal requirements with Matplotlib
+    defaults:
+      run:
+        shell: bash
+    env:
+        MIN_REQUIREMENTS: true
+        MATPLOTLIB: true
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.6
+        name: 'Setup python'
+      - shell: bash -l {0}
+        name: 'Display Python version'
+        run: python -c "import sys; print(sys.version)"
+      - shell: bash -l {0}
+        run: ./build_tools/github/dependencies.sh
+        name: 'Install dependencies'
+      - shell: bash -l {0}
+        run: ./build_tools/github/install.sh
+        name: 'Install nilearn'
+      - shell: bash -l {0}
+        run: ./build_tools/github/test.sh
+        name: 'Run tests'
+
   latest:
     needs: check_skip
     if: ${{ needs.check_skip.outputs.skip == 'false' }}

README.rst

@@ -53,8 +53,7 @@ The required dependencies to use the software are:
 * Nibabel >= 3.0
 * Pandas >= 1.0
 
-If you are using nilearn plotting functionalities or running the
-examples, matplotlib >= 1.5.1 is required.
+If you are using nilearn plotting functionalities or running the examples, matplotlib >= 3.0 is required.
 
 Some plotting functions in Nilearn support both matplotlib and plotly as plotting engines.
 In order to use the plotly engine in these functions, you will need to install both plotly and kaleido, which can both be installed with pip and anaconda.

build_tools/github/dependencies.sh

@@ -3,6 +3,9 @@
 python -m pip install --progress-bar off --upgrade pip setuptools wheel flake8
 if [ ! -z "$MIN_REQUIREMENTS" ]; then
     pip install --progress-bar off --upgrade -r requirements-min.txt
+    if [ ! -z "$MATPLOTLIB" ]; then
+        pip install --progress-bar off --upgrade matplotlib==3.0
+    fi
 else
     pip install --progress-bar off --upgrade -r requirements-dev.txt
 fi