Update Ubuntu runner image (#26)

* Use `ubuntu-latest`.

* Install libuuid.

* Remove old submodule.

* Add updated catch2 dependency.

Author: samsymons

.github/workflows/pr.yml

@@ -11,14 +11,18 @@ jobs:
     name: Unit Tests
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest]
+        os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
 
     steps:
     - uses: actions/checkout@v3
       with:
         submodules: recursive
 
+    - name: Install uuid-dev on Ubuntu
+      if: runner.os == 'Linux'
+      run: sudo apt-get update && sudo apt-get install -y uuid-dev
+
     - name: Run tests
       run: ./run_test.sh
       shell: bash

.gitmodules

@@ -1,3 +1,3 @@
 [submodule "third-party/catch2"]
 	path = third-party/catch2
-	url = https://github.com/duckduckgo/Catch2.git
+	url = https://github.com/catchorg/Catch2.git