Updated newport74000 monochromator
Put connection in the constructor
Corrected port initialization for EdmundOptics photodiode
Merge pull request #261 from ufo-kit/EdmundOptics

Corrected port initialization for EdmundOptics photodiode
Disable Python 3 for the moment
Merge pull request #253 from ufo-kit/newport

Updated newport74000 monochromator
Upgrade of conversion between entered and transmitted value.
Merge pull request #262 from ufo-kit/monochromator

Upgrade of conversion between entered and transmitted value.
Move write_images to concert.storage

because of a future circular dependency between
coroutines.sinks and storage modules
Don't append file extensions by writers
Add file system walker

and image-based implementations. Fixes #259.
Update experiments to use walkers
Fix pep8 in concert.experiments.base
Update experiment tests