message: [skip ci] Remove Appveyor badge on readme
diff: -[![OSx on Azure](https://dev.azure.com/GUDHI/gudhi-devel/_apis/build/status/GUDHI.gudhi-devel?branchName=master)](https://dev.azure.com/GUDHI/gudhi-devel/_build/latest?definitionId=1&branchName=master)
  +[![OSx and Win on Azure](https://dev.azure.com/GUDHI/gudhi-devel/_apis/build/status/GUDHI.gudhi-devel?branchName=master)](https://dev.azure.com/GUDHI/gudhi-devel/_build/latest?definitionId=1&branchName=master)
  [![Linux on CircleCI](https://circleci.com/gh/GUDHI/gudhi-devel/tree/master.svg?style=svg)](https://circleci.com/gh/GUDHI/gudhi-devel/tree/master)
  -[![Win on Appveyor](https://ci.appveyor.com/api/projects/status/976j2uut8xgalvx2/branch/master?svg=true)](https://ci.appveyor.com/project/GUDHI/gudhi-devel/branch/master)
  [![Anaconda Cloud](https://anaconda.org/conda-forge/gudhi/badges/version.svg)](https://anaconda.org/conda-forge/gudhi)
  [![Anaconda downloads](https://anaconda.org/conda-forge/gudhi/badges/downloads.svg)](https://anaconda.org/conda-forge/gudhi)
  