Travis: install pytest-xdist
Remove nonsensical mv from Git commit hook setup instructions
Travis: revert parallel pytest call

Seems just to cause errors.
Remove sqrt from IcosahedralSphereMesh namespace
A cohomology test. This test measures the null space of various operators, which are topology-dependent and therefore are rather nice as tests, since they do not require fine meshes.
mesh file
Added docstrings for each individual test.
Update mesh files to include boundary conditions.

Use pytest to parametrize tests.
Added the cohomology for boundary conditions.
Forgot to check for enriched element in the betti0 test.
Remove travis links on website

Since the travis builder is currently timing out, replace CI links for
Firedrake to the local buildbot, which does run.
Fix test_2dcohomology to work from any directory
Add to_expression to convert iterable to Expression
Allow list of constants in DirichletBC constructor

Use new to_expression to convert iterables to Expression of appropriate
rank.
Update docs for new DirichletBC call signature
added some vector-valued interior facet 0-form tests, marked skip
adding 3D extruded facet tests (currently xfailed)
adding 2D extruded facet tests (currently xfailed)
Add initial test for facets.
Add measures to core types.
Add support for top and bottom facet zero form integrals.