Either appveyor.yml or .appveyor.yml is allowed, let's hide with other dotfiles

.appveyor.yml

@@ -0,0 +1,23 @@
+environment:
+  matrix:
+  - TOXENV: "py27-pytestlatest"
+  - TOXENV: "py34-pytestlatest"
+  - TOXENV: "py35-pytestlatest"
+  - TOXENV: "py36-pytestlatest"
+  - TOXENV: "py37-pytestlatest"
+  - TOXENV: "py38-pytestlatest"
+  - TOXENV: "py38-pytestmaster"
+  - TOXENV: "py38-pytestfeatures"
+
+install:
+  - C:\Python38\python -m pip install -U pip setuptools
+  - C:\Python38\python -m pip install -U tox setuptools_scm
+
+build: false  # Not a C# project, build stuff at the test step instead.
+
+test_script:
+  - C:\Python38\python -m tox
+
+# We don't deploy anything on tags with AppVeyor, we use Travis instead, so we
+# might as well save resources
+skip_tags: true