Get stricter about error handling in powershell.

Still doesn't do anything about subcmds failing. Those have to be
manually checked.

Signed-off-by: Ryan Davis <zenspider@chef.io>

.expeditor/buildkite/artifact.habitat.test.ps1

@@ -1,6 +1,9 @@
 #!/usr/bin/env powershell
 
 #Requires -Version 5
+# https://stackoverflow.com/questions/9948517
+Set-StrictMode -Version Latest
+$PSDefaultParameterValues['*:ErrorAction']='Stop'
 $ErrorActionPreference = 'Stop'
 $env:HAB_ORIGIN = 'ci'
 $env:CHEF_LICENSE = 'accept-no-persist'

habitat/plan.ps1

@@ -1,3 +1,8 @@
+# https://stackoverflow.com/questions/9948517
+Set-StrictMode -Version Latest
+$ErrorActionPreference = "Stop"
+$PSDefaultParameterValues['*:ErrorAction']='Stop'
+
 $pkg_name="inspec"
 $pkg_origin="chef"
 $pkg_version=$(Get-Content "$PLAN_CONTEXT/../VERSION")