Fix and simplify appveyor conda

Author: tpaviot

appveyor.yml

@@ -2,67 +2,21 @@ version: pythonocc-demos-7.5.1.{build}
 
 environment:
 
-  global:
-    # SDK v7.0 MSVC Express 2008's SetEnv.cmd script will fail if the
-    # /E:ON and /V:ON options are not enabled in the batch script interpreter
-    # See: http://stackoverflow.com/a/13751649/163740
-    CMD_IN_ENV: "cmd /E:ON /V:ON /C .\\ci\\appveyor\\obvci_appveyor_python_build_env.cmd"
-  
-    # Workaround for https://github.com/conda/conda-build/issues/636
-    PYTHONIOENCODING: "UTF-8"
-
   matrix:
-    - PYTHON: "C:\\Python37_64"
-      PYTHON_VERSION: "3.7"
-      PYTHON_ARCH: "64"
-      CONDA_PY: "37"
-      CONDA_NPY: "18"
-      CONDA_INSTALL_LOCN: "C:\\Miniconda37-x64"
-    - PYTHON: "C:\\Python38_64"
-      PYTHON_VERSION: "3.8"
-      PYTHON_ARCH: "64"
-      CONDA_PY: "38"
-      CONDA_NPY: "18"
-      CONDA_INSTALL_LOCN: "C:\\Miniconda38-x64"
-    - PYTHON: "C:\\Python39_64"
-      PYTHON_VERSION: "3.9"
-      PYTHON_ARCH: "64"
-      CONDA_PY: "39"
-      CONDA_NPY: "18"
-      CONDA_INSTALL_LOCN: "C:\\Miniconda39-x64"
-
-# We always use a 64-bit machine, but can build x86 distributions
-# with the TARGET_ARCH variable (which is used by CMD_IN_ENV).
-platform:
-    - x64
+    - PYTHON_VERSION: "3.7"
+    - PYTHON_VERSION: "3.8"
+    - PYTHON_VERSION: "3.9"
 
 install:
-    # Set the CONDA_NPY, although it has no impact on the actual build. We need this because of a test within conda-build.
-    - cmd: set CONDA_NPY=19
-    # Remove cygwin (and therefore the git that comes with it).
-    - cmd: rmdir C:\cygwin /s /q
-    # Use the pre-installed Miniconda for the desired arch
-    #
-    # However, it is really old. So, we need to update some
-    # things before we proceed. That seems to require it being
-    # on the path. So, we temporarily put conda on the path
-    # so that we can update it. Then we remove it so that
-    # we can do a proper activation.
-    - cmd: set "OLDPATH=%PATH%"
-    - cmd: set "PATH=%CONDA_INSTALL_LOCN%\\Scripts;%CONDA_INSTALL_LOCN%\\Library\\bin;%PATH%"
+    - cmd: set "PATH=C:\\Miniconda37-x64\\Scripts;C:\\Miniconda37-x64\\Library\\bin;%PATH%"
+    - cmd: conda -V
     - cmd: conda config --set always_yes yes --set changeps1 no
     - cmd: conda update conda
-    - cmd: set "PATH=%OLDPATH%"
-    - cmd: call %CONDA_INSTALL_LOCN%\Scripts\activate.bat
-    - cmd: conda config --set show_channel_urls true
-    - cmd: conda config --add channels https://conda.anaconda.org/dlr-sc
-    - cmd: conda config --add channels https://conda.anaconda.org/tpaviot
+    - cmd: conda create -n testenv python="%PYTHON_VERSION%"
+    - cmd: activate testenv
     - cmd: conda install -c conda-forge pythonocc-core==7.5.1
-    #- cmd: conda install pyqt
-    #- cmd: conda install wxpython
     - cmd: conda install numpy
 
-
 build: off
 
 test_script: