[tor-relays] rise in bridges starting with ~2017-03-28

Hi,

I don't know if the discussion of the thread "22% of bridges run by a single entity?" [1] sparked this, but someone was very busy adding lots of obfs4 bridges.

Normally you would see <50 new bridges per day, in the last few days we saw >120 new bridges per day.

They all run tor 0.2.9.10, support the obfs4 transport and have a nickname that looks like it is generated from a dictionary.

https://github.com/nusenu/tor-network-observations/blob/master/2017-03-29_ma...

You can even see it on metrics: https://metrics.torproject.org/networksize.html

[1] https://lists.torproject.org/pipermail/tor-relays/2017-March/012156.html