Merge branch 'release/v0.0.13' into next
refactor: take out separate excel and csv strategies, use roo for both
remove duplicate file
add comment about roo checking file extension
remove file type specific validators
Merge pull request #9 from rshallit/next

refactor to use same strategy for all spreadsheets
remove some code-smells
version bump
Merge branch 'release/v0.0.14'