boobank: add degiro module

This module talks to the Degiro stock market broker. The website is fairly complex and has a heavyweight Javascript frontend that does a lot of things itself (such as computing the account balance). That makes the module more complex than others, because retrieving the list of current positions is a multi-step process, and retrieving the current account balance is not feasible trivially. (The reason why is because Degiro has no concept of cash, instead it holds all your cash in "cash funds" which are subcompartments of actual monetary funds that even have an ISIN.)
10 jobs from degiro in 0 seconds (queued for 1519 minutes and 32 seconds)
Status Job ID Name Coverage
  Build
failed #10788
build:2.7

failed #10789
build:3

 
  Test
skipped #10791
allowed to fail
lint:2.7
skipped #10794
allowed to fail
lint:3
skipped #10790
pyflakes:2.7
skipped #10793
pyflakes:3
skipped #10792
unittests:2.7
skipped #10795
unittests:3
 
  Deploy
skipped #10796
doc:2.7
skipped #10797
doc:3
 
Name Stage Failure
failed
build:3 Build There is an unknown failure, please try again
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failed
build:2.7 Build There is an unknown failure, please try again
No job trace