fix: response encode mismatch

[marocchino]

About the changes

Ruby's file writing defaults to utf-8, but net http's response seems to be based on the header and ASCII is used by default when no specification is made.
I didn't write any test files, but I verified them as follows:

# run with main branch
bin/spring stop
bin/rails c
> Unleash::Client.new
[Unleash] ERROR: Unable to save backup file. Exception thrown Encoding::UndefinedConversionError:'"\xE3" from ASCII-8BIT to UTF-8'
...
# run with this branch
bin/spring stop
bin/rails c
> Unleash::Client.new
(no error)

Closes #214

Important files

Discussion points

[marocchino]

https://ruby-doc.org/3.2.5/stdlibs/net/Net/HTTP.html#method-i-request_post

[coveralls]

Pull Request Test Coverage Report for Build 11944771961

Details

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 95.385%

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Totals
Change from base Build 11814257586:	0.01%
Covered Lines:	434
Relevant Lines:	455

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💛 - Coveralls

[sighphyre]

Thanks for the fix, seems reasonable

[sighphyre]

LGTM