Adds optional 'params' parameter to all calls

MailChimp Interest Group calls

Adds spacing in function definitions

Merge pull request #6 from GunnarLieb/patch-1

deserializeJson uses wrong argument

Iterates version to 1.1.1

Uses JSONUtil's default 'strictMapping=false'

Adds server question to bug report instructions

Updates gitignore

Fixes Markdown headers

Updates editorconfig and gitignore

Iterates version to 1.1.0

Fixes typos with JSONUtil usage

Adds Code of Conduct and contribution guidelines

Adds JSONUtil for serialization