Resolve "add stats button on home screen and show stats about period length"

Closes #109

See merge request bloodyhealth/drip!41

Resolve "calendar: vertically scrollable or at least swipeable"

Closes #79

See merge request bloodyhealth/drip!49

Resolve "bug: export is missing file extension"

Closes #118

See merge request bloodyhealth/drip!47

Resolve "Add button to export to settings page"

Closes #113

See merge request bloodyhealth/drip!46

Resolve "clean up line length warnings"

Closes #91

See merge request bloodyhealth/drip!43

Upgrade to RN 56 and gradle 3

See merge request bloodyhealth/drip!45