Cleaned up undefined instance variable warnings

[philsturgeon]

Unit test output was hard to read, had a lot of warnings in it. This
code is functionally the same but doesn't trigger those warnings. :)

/Users/psturgeon/.rbenv/versions/2.5.0/lib/ruby/gems/2.5.0/gems/moneta-1.0.0/lib/moneta/expires.rb:31:
warning: assigned but unused variable - expires
................../Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
/Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:78:
warning: instance variable @default_value not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
../Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
./Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
../Users/psturgeon/src/circuitbox/lib/circuitbox/faraday_middleware.rb:69:
warning: instance variable @circuit_breaker_options not initialized
...../Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E./Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E./Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E/Users/psturgeon/src/circuitbox/lib/circuitbox/excon_middleware.rb:89:
warning: instance variable @circuit_breaker_options not initialized
E.....................................

Finished in 0.070928s, 1226.5960 runs/s, 1494.4733 assertions/s.

[matthewshafer]

Thanks for working on this @philsturgeon, now the test output is a bit easier to read.