diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 3bf7e31..ef93221 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -2,6 +2,10 @@ name: Run tests using Conda
 
 on: [push]
 
+strategy:
+  matrix:
+    python-version: [3.6, 3.7, 3.8]
+
 jobs:
   build-linux:
     runs-on: ubuntu-latest
@@ -10,10 +14,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Set up Python 3.8
+    - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        python-version: 3.8
+        python-version: ${{ matrix.python-version }}
     - name: Add conda to system path
       run: |
         # $CONDA is an environment variable pointing to the root of the miniconda directory
diff --git a/experiment_impact_tracker/utils.py b/experiment_impact_tracker/utils.py
index 1dd20a7..2fee82a 100644
--- a/experiment_impact_tracker/utils.py
+++ b/experiment_impact_tracker/utils.py
@@ -11,8 +11,6 @@
 
 import numpy as np
 import pandas as pd
-import psutil
-import ujson
 
 from experiment_impact_tracker.data_utils import *
 from experiment_impact_tracker.data_utils import load_data_into_frame