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: Ie9a6706e1977efafcaad799ac6a68a966c9bb693
(cherry picked from commit 6ab903b68ad0bc42b5122f07d2f60d01c88776b1)
(cherry picked from commit 89006bb424188354048870a8bd401d88af92641a)

.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