Fix python3 incompatibility.
Fix python3 incompatibility.

- unicode.strip is not found on python3
- map returns lazy generator instead of evaluated list.

Natgeoed/djorm-ext-pgarray,niwinz/djorm-pgarray,Natgeoed/djorm-ext-pgarray,natgeo/djorm-ext-pgarray,natgeo/djorm-ext-pgarray,niwinz/djorm-pgarray