Remove deprecated pester.sh script

pester.sh

@@ -1,12 +0,0 @@
-#!/usr/bin/env bash
-
-test -x bin/powershell || { echo >&2 "No bin/powershell, please run './build.sh'"; exit 1; }
-
-./bin/powershell --noprofile -c "Import-Module Microsoft.PowerShell.Platform; Invoke-Pester test/powershell/$1 -OutputFile pester-tests.xml -OutputFormat NUnitXml -EnableExit"
-failed_tests=$?
-
-# XML files are not executable
-chmod -x pester-tests.xml
-
-# Return number of failed tests as exit code (more than 0 will be an error)
-exit $failed_tests