Fix rubocop

Author: Unai Abrisketa

lib/beyond_api/ext.rb

@@ -41,9 +41,9 @@ def underscore
   def camelize(uppercase_first_letter = true)
     string = self
     if uppercase_first_letter
-      string = string.sub(/^[a-z\d]*/) { |match| match.capitalize }
+      string = string.sub(/^[a-z\d]*/, &:capitalize)
     else
-      string = string.sub(/^(?:(?=\b|[A-Z_])|\w)/) { |match| match.downcase }
+      string = string.sub(/^(?:(?=\b|[A-Z_])|\w)/, &:downcase)
     end
     string.gsub(/(?:_|(\/))([a-z\d]*)/) { "#{$1}#{$2.capitalize}" }.gsub("/", "::")
   end

lib/beyond_api/resources/token.rb

@@ -13,8 +13,8 @@ class InvalidSessionError < StandardError; end
     def initialize(session)
       @session = session
 
-      raise InvalidSessionError.new("Invalid session") unless session.is_a? BeyondApi::Session
-      raise InvalidSessionError.new("Session api_url cannot be nil") if session.api_url.nil?
+      raise InvalidSessionError, "Invalid session" unless session.is_a? BeyondApi::Session
+      raise InvalidSessionError, "Session api_url cannot be nil" if session.api_url.nil?
     end
 
     def authorization_code(code)