STY: Dont log info messages by default

[larsoner]

When processing things in a loop I get spammed by a lot of:

colormap sequential: [0.00e+00, 9.68e-01, 1.94e+00] (transparent)
colormap sequential: [0.00e+00, 9.68e-01, 1.94e+00] (transparent)
colormap sequential: [0.00e+00, 9.68e-01, 1.94e+00] (transparent)
colormap sequential: [0.00e+00, 9.68e-01, 1.94e+00] (transparent)

I don't think this is very useful for users in general, so by default we probably shouldn't log it.

[larsoner]

Argh this does not work, I'll probably just set them to logger.debug instead of logger.info

[mwaskom]

+100 on this; I have verbose=0 set all over the place.

[codecov]

Codecov Report

Merging #293 into master will decrease coverage by 0.03%.
The diff coverage is 50.00%.

@@            Coverage Diff             @@
##           master     #293      +/-   ##
==========================================
- Coverage   74.94%   74.90%   -0.04%     
==========================================
  Files           7        7              
  Lines        2594     2594              
  Branches      514      514              
==========================================
- Hits         1944     1943       -1     
- Misses        475      476       +1     
  Partials      175      175              

[larsoner]

Just changed all logger.info to logger.debug, then fixed an MNE install error

[mwaskom]

We could drop 3.5 support? Most pydata packages have...

[larsoner]

Let's do it in another PR. It would be good to do that while also adding 3.8 now that VTK9 is out. But that might require quite a few iterations...