autopep8 --ignore=E501 fixes for chapter 5

(E501 = line too long)
I dislike how autopep8 breaks long lines,
and the lines weren't usually too long here.
Minor updates from new tool
Merge remote-tracking branch 'cam/master' into chap5-style

Conflicts:
	Chapter5_LossFunctions/LossFunctions.ipynb
Ending code cells with a semicolon.
Merge branch 'cam-master' into chap5-style
Not adding or removing semicolons
Merge pull request #183 from eli-b/chap5-style

Chap5 style