Update bridges

See merge request !19

Replace obfs4proxy and snowflake with lyrebird

See merge request !20

Update bridges

See merge request !18

Update bridges, refactor bridge configuration

See merge request !17

Currently this is the same as the default config, except that Azure
is never used. But it may diverge, so let's make sure it's tested.

The URLs and front domains may change again based on input from the Tor team.

Update bridges

See merge request !16

Update Snowflake params and bridges

See merge request !15