try and resolve intermittent travis build problems
try and resolve intermittent travis build problems

There seems to be a problem in some travis builds where some java wrapper files aren't finished writing before the next step of the build happens. This is an attempt to resolve that.
bp-kelley/rdkit,rdkit/rdkit,ptosco/rdkit,bp-kelley/rdkit,adalke/rdkit,jandom/rdkit,jandom/rdkit,rdkit/rdkit,rdkit/rdkit,greglandrum/rdkit,adalke/rdkit,jandom/rdkit,jandom/rdkit,ptosco/rdkit,greglandrum/rdkit,rdkit/rdkit,jandom/rdkit,ptosco/rdkit,adalke/rdkit,jandom/rdkit,bp-kelley/rdkit,rdkit/rdkit,bp-kelley/rdkit,jandom/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,rvianello/rdkit,greglandrum/rdkit,greglandrum/rdkit,ptosco/rdkit,greglandrum/rdkit,rvianello/rdkit,rvianello/rdkit,greglandrum/rdkit,jandom/rdkit,ptosco/rdkit,rvianello/rdkit,rvianello/rdkit,rvianello/rdkit,ptosco/rdkit,greglandrum/rdkit,adalke/rdkit,rdkit/rdkit,greglandrum/rdkit,ptosco/rdkit,rdkit/rdkit,rvianello/rdkit,bp-kelley/rdkit,adalke/rdkit,adalke/rdkit,adalke/rdkit,bp-kelley/rdkit,rdkit/rdkit,rvianello/rdkit,adalke/rdkit,ptosco/rdkit