This was done on a Ubuntu 14.04 system with wxWidgets 3.1.1 installed.
The resulting buildfiles successfully build Audacity on Ubuntu 14.04 (with 3.1.1) and on Travis (with 3.0.0).
This way, building the minsrc tarball doesn't require multiple versions
of Automake to be installed. (Most things were at the 1.11 version, but
some were at the 1.14 version.)
Building minsrc should now work just fine.