Bite 133. Convert an Amazon URL into an affiliation link

Can you help PyBites automate their Amazon affiliation link creation?

Complete the generate_affiliation_link(url) function below which should convert the following links:

https://www.amazon.com/War-Art-Through-Creative-Battles/dp/1936891026/?keywords=war+of+art
https://amazon.com/War-Art-Through-Creative-Battles/dp/1936891026/ref=sr_1_1
https://www.amazon.es/War-Art-Through-Creative-Battles/dp/1936891026/?qid=1537226234
https://www.amazon.co.uk/Pragmatic-Programmer-Andrew-Hunt/dp/020161622X
https://www.amazon.com.au/Python-Cookbook-3e-David-Beazley/dp/1449340377/

... into the following affiliation links respectively:

http://www.amazon.com/dp/1936891026/?tag=pyb0f-20
http://www.amazon.com/dp/1936891026/?tag=pyb0f-20
http://www.amazon.com/dp/1936891026/?tag=pyb0f-20
http://www.amazon.com/dp/020161622X/?tag=pyb0f-20
http://www.amazon.com/dp/1449340377/?tag=pyb0f-20

Hint: regex might be overkill here! Have fun and remember, keep calm and code in Python!