genesis: Ensure no dup validators, or bonded and revoked validators

[ValarDragon]

ref #2229

• Targeted PR against correct branch (see CONTRIBUTING.md)

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.

• Wrote tests

• Added entries in PENDING.md with issue #

• rereviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #2280 into develop will increase coverage by 0.05%.
The diff coverage is 100%.

@@             Coverage Diff             @@
##           develop    #2280      +/-   ##
===========================================
+ Coverage    63.83%   63.89%   +0.05%     
===========================================
  Files          140      140              
  Lines         8666     8680      +14     
===========================================
+ Hits          5532     5546      +14     
  Misses        2754     2754              
  Partials       380      380

[cwgoes]

utACK