Log Message:
py-ICU: updated to 2.5

Version 2.4.3 -> 2.5
--------------------
- added support for turning on -pedantic with gcc or clang
- added support for ICU 67.1
- added wrappers for FormattedValue, ConstrainedFieldPosition, UFieldCategory
- made FormattedValue iterable via nextPosition()
- added wrappers for FormattedDateInterval, FormattedNumber, FormattedList
- added wrappers for FormattedRelativeDateTime and enums
- added wrappers for UNumberFormatFields, UNumberFormatAttribute
- added wrappers for NumberRangeFormatter, FormattedNumberRange and enums
- added icu.ICU_MAX_MAJOR_VERSION global set to largest ICU version supported