ENG-5842 Fix voltify from debian package.
ENG-5842 Don't rebuild venv if version.txt is missing.
Merge pull request #1147 from VoltDB/notest-ENG-5842

ENG-5842 Fix voltify from debian and rpm packages.
Merge branch 'master' of github.com:VoltDB/voltdb into ENG-5712
ENG-5712 Write output file, better messages, and groovy test.