Bump httparty from 0.18.1 to 0.20.0

Bumps httparty from 0.18.1 to 0.20.0.

Changelog

Sourced from httparty's changelog.

0.20.0

Breaking changes

• Require Ruby >= 2.3.0

Fixes

• Marshal.dump fails on response objects when request option :logger is set or :parser is a proc
• Switch :pem option to to OpenSSL::PKey.read to support other algorithms

0.19.1

• Remove use of unary + method for creating non-frozen string to increase compatibility with older versions of ruby

0.19.0

• Multipart/Form-Data: rewind files after read
• add frozen_string_literal pragma to all files
• [Better handling of Accept-Encoding / Content-Encoding decompression (fixes #562)](https://github.com/jnunemaker/httparty/pull/729)

Commits

• 32c57d9 Release 0.20
• 3230642 Update changelog
• 1c09725 Merge pull request #720 from themgt/pem-pkey-algorithm-agonistic
• 9037edf Update changelog
• 2bf82b9 Merge pull request #736 from jnunemaker/require-ruby-23
• 45f20a6 Merge pull request #714 from baberthal/mix-marshal-dump-proc-io
• 9f420c2 Merge branch 'master' into require-ruby-23
• b9c5515 Merge pull request #732 from olleolleolle/patch-1
• 5dcc694 Require ruby >= 2.3.0
• 0d20a4f Release 0.19.1
• Additional commits viewable in compare view