Refactor auth_rate_spec to account for password used in config

[DeezyE]

within /spec/beef/api/auth_rate_spec.rb

beef/spec/beef/api/auth_rate_spec.rb

Lines 9 to 15 in 1ae320c

	before(:all) do
	@config = BeEF::Core::Configuration.instance
	@config.set('beef.credentials.user', "beef")
	@config.set('beef.credentials.passwd', "beef")
	@username = @config.get('beef.credentials.user')
	@password = @config.get('beef.credentials.passwd')

The setting (and using later) of passwords in this manner breaks the test when you set custom env variables for a test user (TEST_BEEF_PASSWD or TEST_BEEF_USER) within the spec/constants.

Suggest using the constants provided in the config or constants without requiring a specific user / pass

[DeezyE]

Once this is resolved, update the wiki https://github.com/beefproject/beef/wiki/BeEF-Testing