travis: Test against the version of Python that Boost 1.46.1 supports.
travis: Test against the version of Python that Boost 1.46.1 supports.

dstoe/vigra,dagophil/vigra,dstoe/vigra,funkey/vigra,funkey/vigra,dagophil/vigra,dagophil/vigra,dagophil/vigra,dagophil/vigra,funkey/vigra,dstoe/vigra,dstoe/vigra,dagophil/vigra,funkey/vigra,funkey/vigra,dstoe/vigra,funkey/vigra,dstoe/vigra,funkey/vigra,dstoe/vigra,dagophil/vigra