Bug#893656: transition: theano 0.9 -> 1.0 - please update lasagne

[Rebecca N. Palmer]

> lasagne - 3 test failures; fixed upstream by https://github.com/Lasagne/Lasagne/pull/836
Latest upstream (37ca134; only packaging change was to drop 
remove-deprecated.patch) doesn't have these failures.  There is a 
warning that cuda_convnet is no longer available with Theano 1.0, but 
that has another dependency (pybuild2) that was never in Debian anyway.

> pyopencl - FTBFS for unrelated reasons (#893050); the theano-using code appears to be build/test scripts (pyopencl/compyte/gen*, test*) we never actually run
Builds after applying the path in #893050; 7 tests fail or crash (in 
Python 2, 6 also in Python 3), but they do this with or without Theano.

> sympy - build hangs at mkdir -p _build/logo (with mkdir using a full CPU core?!), probably unrelated as it also happens without *-theano installed
This hang is because faketime doesn't work well with cowbuilder --login, 
i.e. nothing to do with sympy itself.  Running the testsuite with new 
Theano succeeds.

Hence, it appears that updating lasagne is the only change required to 
work with Theano 1.0, but testing on CUDA-capable hardware would still 
be preferable.