✅ 🐛 fix ci can't download python=3.9

Author: Zeroto521

.travis.yml

@@ -4,7 +4,6 @@ python:
   - "3.6"
   - "3.7"
   - "3.8"
-  - "3.9"
 
 before_install:
   - sudo apt-get update

setup.py

@@ -41,7 +41,6 @@
     "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
     "Programming Language :: Python :: 3.8",
-    "Programming Language :: Python :: 3.9",
 
     "Topic :: Software Development",
     "Topic :: Software Development :: Libraries",