Add CLI command to generate reports

[adelavega]

CLI command "report" could generate reports on data + model independently of estimating the models

[adelavega]

Related to #305

[adelavega]

Here's an example of the TFCE available in nilearn:

https://nilearn.github.io/dev/auto_examples/05_glm_second_level/plot_second_level_one_sample_test.html#sphx-glr-auto-examples-05-glm-second-level-plot-second-level-one-sample-test-py

[adelavega]

Closing in favor of bids-standard/pybids#910

[adelavega]

Actually leaving this open, as I think fitlins should let you create the report, but pybids should host most of the logic