added python 3.8 support; dropped python 3.4 support due to build failure with new requests version

.travis.yml

@@ -1,14 +1,10 @@
 language: python
 python:
   - "2.7"
-  - "3.4"
   - "3.5"
   - "3.6"
-matrix:
-  include:
-    - python: 3.7
-      dist: xenial
-      sudo: true
+  - "3.7"
+  - "3.8"
 install:
   - pip install -r requirements.txt
 script:

setup.py

@@ -34,8 +34,11 @@ setuptools.setup(
     url="https://github.com/jdepoix/youtube-transcript-api",
     packages=setuptools.find_packages(),
     classifiers=(
-        "Programming Language :: Python :: 2",
-        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 2.7",
+        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
         "License :: OSI Approved :: MIT License",
         "Operating System :: OS Independent",
     ),