Merge pull request #117 from bobjansen/master

Further fixes for Chapter 2
fixing figure in chapter1
fixing tryarch plots in chp1 and looking into new data for example (sandbox)
Fixes minor grammar error
Merge pull request #119 from slayton/master

Fixes minor grammar error
Fixed a typo and some whitespace inconsistencies
Merge pull request #120 from elpres/master

Fixed a typo and some whitespace inconsistencies
Fix wrong reference to p_B instead of delta
Merge pull request #121 from tritemio/master

Fix wrong reference to p_B instead of delta
adding ABC
Update Chapter1_Introduction.ipynb

Fixed two typos
Update Chapter1_Introduction.ipynb
Merge pull request #122 from vsl9/master

Update Chapter 1
Correct comment on what code actually does
Merge pull request #123 from JensRantil/minor-comment-fix

Correct comment on what code actually does
adding average income by programming languages statistical mistake
Merge branch 'master' of github.com:CamDavidsonPilon/Probabilistic-Programming-and-Bayesian-Methods-for-Hackers
the example shows 500 samples, not 300
lw variable is used everywhere except here
lowercase x and y are defined (same object), but only x is used. substituting to y makes more sense; minor whitespace edits