Duration calculated as just less than requested

[krisgesling]

Utterance: "start recording for 30 seconds"

Current behaviour:
The duration is calculated to be ~29.794459 seconds.

Expected behaviour:
The duration should be calculated as 30 seconds.

Tips:

• This is handled by the handle_record intent handler around line 111.
• Consider other functions that might be useful like extract_duration
• This handler currently processes both durations and end times.