fixed imports and keys

[jetheurer]

added import datetime; changed key from Alpha_sc to alpha_sc

[wholmgren]

@jetheurer I took a very brief look at your notebooks and it's not clear to me what's different. Can you provide a description of what you've changed? git diff does not work well with IPython notebooks, unfortunately.

[jetheurer]

They were very simple changes. In one notebook I added import datetime and in another i changed the dictionary key from Alpha_sc to alpha_sc

But I ran all the notebooks again to be sure they worked -- so I think that's why the diff is so confusing.

[wholmgren]

Thanks for clarification. That Alpha_sc issue is due to the new sam files in #80.