Remove explorations/ scratch scripts from tracking

The explorations/*.py analysis scripts were unintentionally committed in the
Chunk-3 commit; drop them from the tree and gitignore the directory. Kept
locally as untracked scratch.

Author: Hdpbilly

.gitignore

@@ -36,3 +36,4 @@ Thumbs.db
 
 # Local logs / scratch
 *.log
+explorations/