Where to put beam energy?

[joelvbernier]

As you know, the material spec currently carries the beam energy along, as it needs it to calculate bragg angles for the active hkls... However, it would seem appropriate to put the beam energy in the instrument config. I propose that we either:

• move the material spec from pickles to yaml and generate material classes on the fly why needed; or
• add to the instrument config anyhow and use that value to override what might be in the material class as loaded...

Thoughts?

[joelvbernier]

This is now in the new instrument config as of v0.5