Pass option to official InChI API to ignore stereochemistry.

Took me a while to track down the option and how to pass it around,
but I think this finally closes #138 and silences all those
   [17:48:35] WARNING: Omitted undefined stereo
warnings that have been plaguing us!
Revert "Temporary tweak to .travis.yml for universalDatabase branch"

This reverts commit b093ca708e15a910a990f56ddd9e9cfc13692df5.