[MRG] Cleanup minimal build and add separate build for pep8 (#210)

* cleanup requiorement minimal

* add pep8 build

* cleanup sklearn

* skip test if no sklearn

* debug build yaml

* comment error out in test (test sklearn)

* maybe small stuff for better robustness : copy the sub-array

* bump verison minimal build

* update version strict requireent

* update version strict requirement last change

2 files changed, 28 insertions, 18 deletions

diff --git a/.github/requirements_strict.txt b/.github/requirements_strict.txt
index d7539c5..9a1ada4 100644
--- a/.github/requirements_strict.txt
+++ b/.github/requirements_strict.txt
@@ -1,7 +1,4 @@
-numpy==1.16.*
-scipy==1.0.*
-cython==0.23.*
-matplotlib
-cvxopt
-scikit-learn
+numpy
+scipy>=1.3
+cython
 pytest
diff --git a/.github/workflows/build_tests.yml b/.github/workflows/build_tests.yml
index 41b08b3..fa814ba 100644
--- a/.github/workflows/build_tests.yml
+++ b/.github/workflows/build_tests.yml
@@ -30,14 +30,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install flake8 pytest "pytest-cov<2.6" codecov
-        pip install -U "sklearn"
-    - name: Lint with flake8
-      run: |
-        # stop the build if there are Python syntax errors or undefined names
-        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
-        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
-        flake8 examples/ ot/ test/ --count --max-line-length=127 --statistics
+        pip install pytest "pytest-cov<2.6" codecov
     - name: Install POT
       run: |
         pip install -e .
@@ -48,6 +41,29 @@ jobs:
       run: |
         codecov
 
+  pep8:
+    runs-on: ubuntu-latest
+    strategy:
+       max-parallel: 4
+       matrix:
+         python-version: [3.8]
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install flake8 
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 examples/ ot/ test/ --count --max-line-length=127 --statistics
 
   linux-minimal-deps:
 
@@ -55,7 +71,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: [3.6]
+        python-version: [3.8]
 
     steps:
     - uses: actions/checkout@v1
@@ -68,7 +84,6 @@ jobs:
         python -m pip install --upgrade pip
         pip install -r .github/requirements_strict.txt
         pip install pytest
-        pip install -U "sklearn"
     - name: Install POT
       run: |
         pip install -e .
@@ -95,7 +110,6 @@ jobs:
          python -m pip install --upgrade pip
          pip install -r requirements.txt
          pip install pytest "pytest-cov<2.6"
-         pip install -U "sklearn"
      - name: Install POT
        run: |
          pip install -e .
@@ -122,7 +136,6 @@ jobs:
         python -m pip install --upgrade pip
         pip install -r requirements.txt
         pip install pytest "pytest-cov<2.6"
-        pip install -U "sklearn"
     - name: Install POT
       run: |
         pip install -e .