use dashj 0.18.1-SNAPSHOT for Import Private Key improvements

[HashEngineering]

Issue being fixed or feature implemented

Try fixing sync issues.

Related PR's and Dependencies

Screenshots / Videos

How Has This Been Tested?

• [ ] QA (Mobile Team)

Checklist:

• [ ] I have performed a self-review of my own code and added comments where necessary
• [ ] I have added or updated relevant unit/integration/functional/e2e tests

[HashEngineering]

We don't need this any more as the master branch is on dashj 0.18.1 now.