Add Missing Documentation

[mdashti]

Here is the list of missing documentation:

• filtering tests using regex
• how to run tests in parallel and distributed mode

[maleadt]

I ran into this trying to get the distributed mode running. I currently came up with the following runtests.jl:

using Distributed
addprocs(...)

@everywhere using XUnit
runtests("setup.jl")
# setup.jl doesn't need to contain anything, but `runtests` needs to
# be invoked in order to set `GLOBAL_XUNIT_STATE`. seems like a bug.

# the testset needs to be included on all workers,
# or everything will just hang...
@everywhere @tesetset runner=DistributedTestRunner() begin
    include("tests.jl")
end

I tried to include tests.jl from setup.jl in order to get the filtering to work, but then the all workers run all tests, so it looks like that isn't the intended design.