Fix issue 99

[FilippoPetroli]

Solves issue #99

[codecov]

Codecov Report

Merging #137 (357741d) into master (b313ec1) will decrease coverage by 0.02%.
The diff coverage is 100.00%.

❗ Current head 357741d differs from pull request most recent head 598a73c. Consider uploading reports for the commit 598a73c to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #137      +/-   ##
==========================================
- Coverage   88.83%   88.81%   -0.02%     
==========================================
  Files          14       14              
  Lines         770      769       -1     
==========================================
- Hits          684      683       -1     
  Misses         86       86              

Impacted Files	Coverage Δ
scrapy_poet/api.py	100.00% <100.00%> (ø)

[FilippoPetroli]

Hi @kmike
I fixed the issue. I saw that there are some silenced test that mention DummyResponse so maybe there are edges to trim. I wrote a basic test but if you prefer, I can write more tests.
Thanks

cc @felipeboffnunes

[kmike]

Hey! The original issue was that .replace doesn't work; could you please add a test for this, or maybe even change this test to check .replace?

Users shouldn't be creating DummyResponse instances themselves, but they might have code which calls response.replace.

[kmike]

Looks good overall, thanks @FilippoPetroli!