Read Next Intent Improvements

[ineshbose]

Currently, reading the next class is pretty limited.

In an earlier version, read_next was a separate intent, but now is integrated with read_timetable. It is called when there is no time found when parsing text.

However, the bot just reads the next class from the same day.
A user may require their next class, be it next week.
Another example could be "my next Java Programming class".

[ineshbose]

Implemented a get_one() method in Timetable that's currently not as efficient or neat as it can be.
Another issue is figuring out class names that the parser has never come across. Course names are also usually university specific so hardcoding is bad.