No auto-update conda

Author: isuruf

.appveyor.yml

@@ -20,6 +20,7 @@ environment:
 
 install:
   - call %CONDA_INSTALL_LOCN%\Scripts\activate.bat
+  - conda config --set auto_update_conda false
   - conda config --add channels conda-forge --force
   - conda install --yes --quiet flang jom
   - call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" amd64