Initialize pants

Followed these instructions:
https://www.pantsbuild.org/docs/installation
https://www.pantsbuild.org/docs/gitignore

NB: The docs were reorganized after this commit was created March 2021.
So, this commit used these instructions (in current docs links):
https://www.pantsbuild.org/docs/manual-installation
https://www.pantsbuild.org/docs/initial-configuration (steps 1 and 4)

Author: cognifloyd

.gitignore

@@ -50,6 +50,12 @@ nosetests.xml
 htmlcov
 benchmark_histograms/
 
+# Pants workspace files
+/.pants.d/
+/dist/
+/.pids
+/.pants.workdir.file_lock*
+
 # Mr Developer
 .idea
 .DS_Store