Add build workflow, deprecate travis

Author: mnovozhylov

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, macos-latest]
-        python: [ '3.8' ]
+        python: [ '3.9' ]
 
     name: Python ${{ matrix.python }}
     steps:

noxfile.py

@@ -54,6 +54,7 @@ def build(session):
     session.install("setuptools")
     session.install("wheel")
     session.install("twine")
+    session.install("types-requests")
     session.run("rm", "-rf", "dist", "build", external=True)
     session.run("python", "setup.py", "--quiet", "sdist", "bdist_wheel")