Add .pdkignore to exclude some files from tar ball

We've seen release job failures caused by too large tarball, which
contains irrelevant files like git history.

Let's exclude these files to reduce size of the archive.

The file is copied from the puppetlabs repositories with some files
specific to OpenStack projects added.

Change-Id: Ifdb9d32c7dd5f4b849982dfd3424602f381a1ef8
(cherry picked from commit 782dd2aec4de431629fa1e213cec3aaf963fdb2a)

.pdkignore

@@ -0,0 +1,51 @@
+# common list used in puppetlabs repos
+.git/
+.*.sw[op]
+.metadata
+.yardoc
+.yardwarns
+*.iml
+/.bundle/
+/.idea/
+/.vagrant/
+/coverage/
+/bin/
+/doc/
+/Gemfile.local
+/Gemfile.lock
+/junit/
+/log/
+/pkg/
+/spec/fixtures/manifests/
+/spec/fixtures/modules/*
+/tmp/
+/vendor/
+/convert_report.txt
+/update_report.txt
+.DS_Store
+.project
+.envrc
+/inventory.yaml
+/spec/fixtures/litmus_inventory.yaml
+/.fixtures.yml
+/Gemfile
+/.gitattributes
+/.gitignore
+/.pdkignore
+/.puppet-lint.rc
+/Rakefile
+/rakelib/
+/.rspec
+/..yml
+/.yardopts
+/spec/
+/.vscode/
+/.sync.yml
+/.devcontainer/
+# OpenStack-specific files
+/bindep.txt
+/.gitreview
+/setup.cfg
+/setup.py
+/tox.ini
+/.zuul.yaml