Try new Travis infrastructure

Supposed to be faster, per:
http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/
Merge pull request #34 from synthicity/new-travis

Try new Travis infrastructure
functionality for querying OSM API
Functions for processing OSM queries into DataFrames

Can get DataFrames of nodes, ways, and waynodes.
Waynodes are essentially a join index for nodes and ways,
though it's a DataFrame for consistency with the others.
add "highway" filter to way query