Merge pull request #108 from ChrisBeaumont/master

Custom adjacency logic
Reload bugfix. Closes #106
Merge pull request #110 from ChrisBeaumont/106

Reload bugfix
First attempt at post-pruning dendrograms.
Moved post-pruning into Dendrograms.
First attempt at merging branches.
Clean-up removal section.
Use isinstanceto check is_independent.
Merge failed leaves into siblings.
Revamped pruning scheme. Iterates until all pruning is done.
Use fill_footprint. Removed re-assigning idx.
Set recursive to False.
Copy _stuctures_dict for keep_structures.
Added pruning test.
Add .all() to test.
Tweak post prune logic, min_delta criteria