[Ubuntu] Migrate tests to Pester (#2340)

* Add Pester tests

* Fix incorrect merging

* Remove swift test from installing script

* Minor fix

* Remove Haskell tests from commons tests

* Fix selenium test

* Fix SVN test

* Fix pipx tests

* Debug

* Fix pipx packages test

* Skip pipx for 16.04

images/linux/scripts/installers/mono.sh

@@ -4,6 +4,8 @@
 ##  Desc:  Installs Mono
 ################################################################################
 
+source $HELPER_SCRIPTS/invoke-tests.sh
+
 LSB_CODENAME=$(lsb_release -cs)
 
 # Test to see if the software in question is already installed, if not install it
@@ -14,13 +16,4 @@ echo "deb https://download.mono-project.com/repo/ubuntu stable-$LSB_CODENAME mai
 apt-get update
 apt-get install -y --no-install-recommends apt-transport-https mono-complete nuget
 
-# Run tests to determine that the software installed as expected
-echo "Testing to make sure that script performed as expected, and basic scenarios work"
-if ! command -v mono; then
-    echo "mono was not installed"
-    exit 1
-fi
-if ! command -v nuget; then
-    echo "nuget was not installed"
-    exit 1
-fi
+invoke_tests "Tools" "Mono"