Scaffold fiken gem: gemspec, dev tooling, rubocop, and CI

fiken.gemspec

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require_relative "lib/fiken/version"
+
+Gem::Specification.new do |spec|
+  spec.name = "fiken"
+  spec.version = Fiken::VERSION
+  spec.authors = ["Runar Ingebrigtsen"]
+  spec.email = ["runar@rin.no"]
+
+  spec.summary = "Ruby client for the Fiken API v2"
+  spec.description = "A resource-oriented Ruby client for the Fiken accounting API (v2), " \
+                     "with personal-token and OAuth2 authentication, pagination, and error handling."
+  spec.homepage = "https://github.com/runari/fiken"
+  spec.license = "MIT"
+  spec.required_ruby_version = ">= 3.1"
+
+  spec.metadata["homepage_uri"] = spec.homepage
+  spec.metadata["source_code_uri"] = spec.homepage
+  spec.metadata["changelog_uri"] = "#{spec.homepage}/blob/main/CHANGELOG.md"
+  spec.metadata["rubygems_mfa_required"] = "true"
+
+  spec.files = Dir["lib/**/*.rb", "README.md", "CHANGELOG.md", "LICENSE.txt"]
+  spec.require_paths = ["lib"]
+
+  spec.add_dependency "faraday", "~> 2.0"
+  spec.add_dependency "faraday-multipart", "~> 1.0"
+  spec.add_dependency "faraday-retry", "~> 2.0"
+end