minor typos in Ch02

[Pejhan]

I should firstly thank the author of this book @wesm for his major contributions to the Pandas community and also for this book which I am reading eagerly and thoroughly.
so might I hint some minor typos in chapters I have covered so far:

p.36. The definition does not corespond with what the code is implying:

p.46. incorrect use of single quotations instead of double:

[Wes McKinney]

Will be fixed in the 3rd edition. Thanks!