[MRG] ADD: Brain.remove_foci()

[christianbrodbeck]

Seemed like it was missing and simple enough to add.

[mwaskom]

Do we use this style of api for any of the other kinds of features that can be added?

[christianbrodbeck]

Yes, remove_data() and remove_labels(), glad you asked :)

[christianbrodbeck]

We could add a new Brain attribute to keep track of unnamed foci too, but it would add some more overhead...

[codecov-io]

Codecov Report

Merging #251 into master will increase coverage by 0.13%. The diff coverage is 100%.

@@            Coverage Diff            @@
##           master    #251      +/-   ##
=========================================
+ Coverage   74.96%   75.1%   +0.13%     
=========================================
  Files           7       7              
  Lines        2477    2494      +17     
  Branches      494     500       +6     
=========================================
+ Hits         1857    1873      +16     
- Misses        447     448       +1     
  Partials      173     173

[larsoner]

Thanks @christianbrodbeck