Uses GitHub Action for PyPI deployments

Travis is running a too outdated setuptools version for deploying.
Also we can't seem to upgrade it. The deployment error was:
```
Traceback (most recent call last):
  File "setup.py", line 3, in <module>
    from setuptools import setup, find_namespace_packages
ImportError: cannot import name find_namespace_packages
InvalidDistribution: Cannot find file (or expand pattern): 'dist/*'
```

.github/workflows/pypi-release.yml

@@ -0,0 +1,25 @@
+name: PyPI release
+on: [push]
+
+jobs:
+  pypi:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.x
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.x
+    - name: Install dependencies
+      run: |
+        python -m pip install --user --upgrade setuptools wheel
+    - name: Build
+      run: |
+        python setup.py sdist bdist_wheel
+        python setup_meta.py sdist bdist_wheel
+    - name: Publish package
+      # if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
+      uses: pypa/gh-action-pypi-publish@v1.1.0
+      with:
+        user: __token__
+        password: ${{ secrets.pypi_password }}

.github/workflows/pythonapp.yml

@@ -1,4 +1,4 @@
-name: Garden flower
+name: Garden mapview
 on: [push, pull_request]
 
 jobs:
@@ -144,3 +144,18 @@ jobs:
         git add .
         git commit -a -m "Docs for git-$GITHUB_SHA"
         git push origin gh-pages -f
+
+  pypi:
+    runs-on: ubuntu-18.04
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.x
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.x
+    - name: Publish package
+      # if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
+      uses: pypa/gh-action-pypi-publish@v1.1.0
+      with:
+        user: __token__
+        password: ${{ secrets.pypi_password }}

.travis.yml

@@ -11,14 +11,3 @@ install:
 
 script:
   - docker run -e DISPLAY -v /tmp/.X11-unix:/tmp/.X11-unix mapview-linux /bin/sh -c 'tox'
-
-# Deploy to PyPI using token set in `PYPI_PASSWORD` environment variable
-# https://pypi.org/manage/account/token/
-# https://travis-ci.com/github/kivy-garden/mapview/settings
-deploy:
-  provider: pypi
-  distributions: sdist bdist_wheel
-  user: "__token__"
-  on:
-    tags: true
-    repo: kivy-garden/mapview

kivy_garden/mapview/_version.py

@@ -1 +1 @@
-__version__ = '1.0.2.dev0'
+__version__ = '1.0.2'