version bumps for `v0.3.1`

[plebhash]

Similar to #275

[plebhash]

#365 is bumping:

• bitcoin_core_sv2 from 0.1.0 to 0.1.1
• jd_server_sv2 from 0.1.0 to 0.1.1
• jd_client_sv2 from 0.1.0 to 0.1.1
• pool_sv2 from 0.2.0 to 0.2.1

[GitGab19]

#370 bumped translator_sv2 from 0.2.0 to 0.2.1