[v0.0.6] Add time difference

What's Changed

• Add DiffDataFrameTransformer by @durandtibo in #257
• Add TimeDiffDataFrameTransformer by @durandtibo in #258
• Improve testing by @durandtibo in #259
• Add time difference in multithumos by @durandtibo in #260
• Update multithumos dataset test by @durandtibo in #261
• Add time difference in breakfast by @durandtibo in #262
• Add time difference in EPIC-KITCHEN-100 by @durandtibo in #263
• Add time difference in Ego4d by @durandtibo in #264
• Release version 0.0.6 by @durandtibo in #265

Full Changelog: v0.0.5...v0.0.6