This patch release fixes two potential issues with Pre-Vote which was added in 1.7.0. One of these has been observed in a single deployed instance but we've been unable to replicate the exact conditions so impact is difficult to assess. Out of an abundance of caution we strongly recommend all 1.7.0 users upgrade to 1.7.1 to avoid this issue occurring.

1. #605 Fixes the observed issue where a node looses leadership but is unable to get pre-votes accepted due to followers thinking it's still the leader. This was an implementation bug.
2. #609 fixes a theoretical issue (not come up with an actual reproduction yet) where a very specific sequence of pre-votes could artificially prevent cluster followers from holding elections even though there is no active leader succeeding to get a quorum of pre-vote responses.