Release v0.3.7

[tyru]

• Write release notes (issues/PR)
• Merge changes in devel branch into master branch
  • Bump version number of voltVersion variable in subcmd/version.go
  • Add new features to README.md
  • Make 6 binaries: {linux,windows,darwin}_{386,amd64} with make release
  • Merge devel
• Push release tag
• Upload binaries and publish release notes