run tests_run in parallel

python pytest-xdist; we haven't been using this;
tests_run_all seem to fail with this (Swarming already)
add external cmake module to determin number for CPU cores
execute python unittests in parallel

pytest-xdist -n
Removed remaining LPF code and updated antiquated tests based on LPF code.
Fixed comment explaining use of RecordSensor.py
Modified travis.yml file to stop running deleted test
Merge branch 'master' into parallel_unittests
Revert "add external cmake module to determin number for CPU cores"

This reverts commit f46362b6e31fd460d5149a812c4c36d2b11fac92.
Revert "execute python unittests in parallel"

This reverts commit a05f97b4013971e5cf0229b07b0ab018ed6bf3b6.
parallel tests: use harcoded 2 threads

not much improvement was observed otherwise.
Merge branch 'master' into parallel_unittests

Conflicts:
	CMakeLists.txt
Merge branch 'master' into iss389

Conflicts:
	nupic/frameworks/opf/exp_generator/__init__.py
	nupic/frameworks/prediction/GUIs.py
	nupic/frameworks/prediction/callbacks.py
	nupic/frameworks/prediction/experiment.py
	nupic/frameworks/prediction/experimentdeschelpers.py
	nupic/frameworks/prediction/helpers.py
	nupic/frameworks/prediction/postprocess/__init__.py
	nupic/frameworks/prediction/postprocess/classificationstats.py
	nupic/frameworks/prediction/postprocess/inputpredictionstats.py
	nupic/frameworks/prediction/postprocess/knnregressionstats.py
	nupic/frameworks/prediction/postprocess/linearregressionstats.py
	nupic/frameworks/prediction/postprocess/ngramstats.py
	nupic/frameworks/prediction/postprocess/poormanstats.py
	nupic/frameworks/prediction/postprocess/postprocess.py
	nupic/frameworks/prediction/postprocess/spstats.py
	nupic/frameworks/prediction/utils.py
	nupic/regions/CLARegion.py
	nupic/regions/CLARegionSimple.py
fix mistake in merge
Merge pull request #964 from jaredweiss/iss389

Issue #389: removing old LPF code
Moving pip requirements into archive.
Adding retry to pip install
Merge branch 'retry-pip-install' into archive-pip-requirements
Merge pull request #976 from rhyolight/retry-pip-install

Adding retry to pip install
Merge branch 'master' of github.com:numenta/nupic into archive-pip-requirements
Merge pull request #975 from rhyolight/archive-pip-requirements

Moving pip requirements into archive.