Fix whitespace from commit 317c703 [1/1]

[Problem]
Commit 317c703, which introduced min/avg/max rendering next to the key used 4 spaces instead of tabs for indentation.

[Solution]
Change 4 space indentation to tabs.
Merge pull request #26 from mufasa72/white_space_fixing

Fix whitespace from commit 317c703 [1/1]