Add a Timezone Classifier

[kharrigian]

Based on Will Myerson's use case. Create a model that ingests UTC timestamps and outputs an estimated timezone (based on distribution). We will want to look into the resolution at which posting times are represented (e.g. hourly vs. sub-hourly). We will want to experiment with the number of timezones included in the output -- e.g. consider merging certain timezones.