Text (yaml) report for download

[mccalluc]

• Fix Download Text report #173
• Fix "Please wait" while notebook builds? #177
• Fix Return results from execution of templated code #110

For reviewer:

• Is the template code understandable?
• Is the generated code in the notebook ok?
• Is the format of the report ok? (Not expecting you to mind-read hypothetical future users, but anything that should just be fixed now?)

[ekraffmiller]

For the report, it looks good, but I think it would be helpful for the user if all the imports for the release were listed.
For example, this is the generated report I got:

inputs:
  data: /var/folders/sv/ps25r8d562z0jzv4y4c_yn7c0000gq/T/fileupload-f2gfx9jw/tmppn4cvg9x/0.csv
outputs:
  educ:
    accuracy: 3.375617766595713
    confidence: 0.95
    histogram:
      (-inf, 1]: 33
      (1, 2.5]: 14
      (10, 11.5]: 167
      (11.5, 13]: 254
      (13, 14.5]: 53
      (14.5, 16]: 36
      (2.5, 4]: 57
      (4, 5.5]: 24
      (5.5, 7]: 54
      (7, 8.5]: 47
      (8.5, 10]: 261

I think it would be good to also include, the epsilon, weight, and maybe number of bins? (Although that is shown in the actual result)

[mccalluc]

I think this adds all the required info, but we're just inserting the values into the generated code: The values also occur earlier in the template, but they aren't stored into variables. Doing that would add a level of generality that would interfere with the clarity of the examples at the top of the notebook, which I think are the priority... but I could be wrong.

[ekraffmiller]

I think it looks good, I agree that you don't need to change the notebook to put the values into variables.