(maint) Fix failing acceptance test

The test previously could find `puppet` in the load path, but that has
mysteriously disappeared from the test setup and/or puppetserver
container. This change adds the /opt/puppetlabs/bin paths found in the
Dockerfile for puppetserver-standalone to the path so puppet is found.

spec/acceptance/lookup_spec.rb

@@ -6,9 +6,10 @@
 
 describe 'lookup with vault configured to accept certs from puppetserver' do
   before(:all) do
-    # install here doesn't really install, it just moves the module over to
-    # the host machine; after install, the test needs to move it somewhere
-    # on the module path.
+    # Since beaker has not run the PrebuiltSteps to add /opt/puppetlabs/* to the
+    # PATH, add the directories to the top of the /etc/bash.bashrc so the dirs
+    # are available for all non-interactive bash shells.
+    on(master, 'sed -i \'1s/^/PATH=\/opt\/puppetlabs\/server\/bin:\/opt\/puppetlabs\/puppet\/bin:\/opt\/puppetlabs\/bin:$PATH\n/\' /etc/bash.bashrc')
     install_module_on(master)
     vault = find_host_with_role('vault')
     scp_to(vault, 'spec/acceptance/fixtures/unseal.sh', '/root/unseal.sh')