fix spectral related testing errors
COSMIT and unused lines
FIX further improve the thresholds
FIX discretization test have shape problem, use coo_matrix instead of LabelBinarizer
Addressing @ogrisel's comments
ENH: Simplify the shape of (n_)classes_ for single output trees
COSMIT Mean Shift docs.
ENH: Simplify the shape of (n_)classes in forest
PEP8
TEST: regression test for shape of (n_)classes
TEST: enforce flat classes_
What's new: API changes
ENH: better names for variables
Merge pull request #1441 from kuantkid/fix_spectral_test

Fix spectral embedding related tests
What's new: added :class: keyword
FIX: convert predictions into a numpy array
FIX: docstring tests
Merge pull request #1445 from glouppe/tree-shape

MRG: Simplify the shape of (n_)classes_ for single output trees/forests
What's new: typo
Display the test names to understand which test is triggering the segfault on jenkins