autopep8 --ignore=E501 fixes.

The code in this chapter was already fixed so the
improvement is debatable.
Merge branch 'master' of https://github.com/CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers

Conflicts:
	Chapter1_Introduction/Chapter1_Introduction.ipynb
Ending code cells with a semicolon.
Merge branch 'cam-master' into chap1-style
Not adding or removing semicolons
Merge pull request #186 from eli-b/chap1-style

autopep8 --ignore=E501,E703 fixes.