Support not a utf-8 encoding

[KwangYeol]

Thank you for your nice project!

Please add an argument encoding to decode that does not utf-8 encoded pages.

gazpacho/gazpacho/get.py

Line 51 in ecd53af

content = response.read().decode("utf-8")

I tried EUC-KR encoded page and got an error message.

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xbd in position 95: invalid start byte