adding 3.8 to travis and appveyor (python-telegram-bot#1543)

Fixes python-telegram-bot#1542

Author: Poolitzer

.travis.yml

@@ -14,6 +14,8 @@ matrix:
       dist: xenial
     - python: pypy3.5-5.10.1
       dist: xenial
+    - python: 3.8-dev
+      dist: xenial
   allow_failures:
     - python: pypy2.7-5.10.0
     - python: pypy3.5-5.10.1

appveyor.yml

@@ -2,14 +2,15 @@ environment:
 
   matrix:
     # For Python versions available on Appveyor, see
-    # http://www.appveyor.com/docs/installed-software#python
+    # https://www.appveyor.com/docs/windows-images-software/#python
     # The list here is complete (excluding Python 2.6, which
     # isn't covered by this document) at the time of writing.
 
     - PYTHON: "C:\\Python27"
     - PYTHON: "C:\\Python35"
     - PYTHON: "C:\\Python36"
     - PYTHON: "C:\\Python37"
+    # - PYTHON: "C:\\Python38"
 
 branches:
   only: