diff --git a/.travis.yml b/.travis.yml
index 1bc28f53..3a27bac7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,22 +1,13 @@
 language: python
+dist: xenial
 python:
-    - 3.6
+    - "3.7"
 
-before_install:
-    - sudo apt-get update
-
-    - wget https://repo.continuum.io/miniconda/Miniconda2-latest-Linux-x86_64.sh -O miniconda.sh;
-    - bash miniconda.sh -b -p $HOME/miniconda
-    - export PATH="$HOME/miniconda/bin:$PATH"
-    - conda update --yes conda
-    - conda config --add channels conda-forge
 install:
-    - conda install --yes python=$TRAVIS_PYTHON_VERSION pip numpy scipy matplotlib
-    #- pip install -r requirements.txt
+    - pip install tox-travis==0.12 tox==3.12.1
 
-# command to run tests
 script:
-    - if [[ $TRAVIS_PYTHON_VERSION == '3.6' ]]; then pytest tests/*; fi
+    - tox
 
 notifications:
     email:
diff --git a/argoverse/visualization/colormap.py b/argoverse/visualization/colormap.py
index bc6869f2..a858b206 100644
--- a/argoverse/visualization/colormap.py
+++ b/argoverse/visualization/colormap.py
@@ -23,7 +23,7 @@
 import numpy as np
 
 
-def colormap(rgb=False):
+def colormap(rgb: bool = False) -> np.ndarray:
     color_list = np.array(
         [
             0.000, 0.447, 0.741,