Real-time module for EQcorrscan

[calum-chamberlain]

Because the codes are reasonably efficient, and allow for distributed computing, it wouldn't be too difficult, using the obspy seedlink module, to compute detections in near real-time.

This pull request serves as a starting point for that module.

To do:

• Generate real-time functions for Template and Detector objects;
• Some form of real-time plotting routines;
• Tests for real-time functions.

[coveralls]

Coverage increased (+1.5%) to 77.564% when pulling 5decc04 on feature/real-time into 94da62a on develop.