Adds .dockerignore file to limit size of podman image context

Signed-off-by: Jiri Podivin <jpodivin@redhat.com>
Change-Id: Ibadbe86370be7d0afccaf8960baaac03bd4eac63

.dockerignore

@@ -0,0 +1,55 @@
+# Docker/Podman image doesn't need any files that git doesn't track.
+#Therefore the .dockerignore largely follows the structure of .gitignore.
+# C extensions
+*.so
+# Packages
+*.egg*
+*.egg-info
+dist
+build
+eggs
+parts
+bin
+var
+sdist
+develop-eggs
+.installed.cfg
+lib
+lib64
+# Installer logs
+pip-log.txt
+# Unit test / coverage reports
+cover/
+.coverage*
+!.coveragerc
+.tox
+nosetests.xml
+.testrepository
+.venv
+.stestr/*
+# Translations
+*.mo
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+# Complexity
+output/*.html
+output/*/index.html
+# Sphinx
+doc/build
+doc/source/reference/api/
+# pbr generates these
+AUTHORS
+ChangeLog
+# Editors
+*~
+.*.swp
+.*sw?
+# Files created by releasenotes build
+releasenotes/build
+# Ansible specific
+hosts
+*.retry
+#Vagrantfiles, since we are using docker
+Vagrantfile.*