diff --git a/.travis.yml b/.travis.yml
index 721f970..10deb0a 100644
--- a/.travis.yml
+++ b/.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:
diff --git a/README.md b/README.md
index d2f3e60..6c2735a 100644
--- a/README.md
+++ b/README.md
@@ -70,7 +70,7 @@ YouTubeTranscriptApi.get_transcripts(video_ids, languages=['de', 'en'])
 If you want to list all transcripts which are available for a given video you can call:
 
 ```python
-transcript_list = YouTubeTranscriptApi.list_transcripts(video_id, languages=['de', 'en'])
+transcript_list = YouTubeTranscriptApi.list_transcripts(video_id)
 ```
 
 This will return a `TranscriptList` object  which is iterable and provides methods to filter the list of transcripts for specific languages and types, like:
diff --git a/requirements.txt b/requirements.txt
index f9ad916..0b8ea35 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
-requests
+requests==2.24.0
 
 # testing
-mock
-httpretty
-coverage
-coveralls
\ No newline at end of file
+mock==3.0.5
+httpretty==0.9.7
+coverage==5.2.1
+coveralls==1.11.1
diff --git a/setup.py b/setup.py
index 1490707..9ab3e33 100644
--- a/setup.py
+++ b/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",
     ),
diff --git a/youtube_transcript_api/_api.py b/youtube_transcript_api/_api.py
index 389cf31..e647041 100644
--- a/youtube_transcript_api/_api.py
+++ b/youtube_transcript_api/_api.py
@@ -1,8 +1,8 @@
 import requests
-try:
+try: # pragma: no cover
     import http.cookiejar as cookiejar
     CookieLoadError = (FileNotFoundError, cookiejar.LoadError)
-except ImportError:
+except ImportError: # pragma: no cover
     import cookielib as cookiejar
     CookieLoadError = IOError
 
diff --git a/youtube_transcript_api/test/test_api.py b/youtube_transcript_api/test/test_api.py
index a081711..5f95451 100644
--- a/youtube_transcript_api/test/test_api.py
+++ b/youtube_transcript_api/test/test_api.py
@@ -21,8 +21,11 @@ from youtube_transcript_api import (
 
 
 def load_asset(filename):
-    with open('{dirname}/assets/{filename}'.format(dirname=os.path.dirname(__file__), filename=filename)) as file:
-        return file.read()
+    filepath = '{dirname}/assets/{filename}'.format(
+        dirname=os.path.dirname(__file__), filename=filename)
+    
+    with open(filepath, mode="rb") as file:
+        return file.read().decode('utf-8')
 
 
 class TestYouTubeTranscriptApi(TestCase):