Rewrote MetricController specs to more correct format. Added test that check that after metric update new report shouldn't be created and associated report should be updated.
Removed #show for MetricController.
Authorization in a controller specs replaced with stubs for faster tests.
Also added format documentation to .rspec.
Fixed bug in a MetricController destroy spec.
Refactored ReportsController specs. Added specs to  'when not logged in' context.
Refactored SettingsController specs.
Fixed spelling errors.
Factory for each model moved to a separate file.
Refactored Metric specs.
Rewrote specs for #previous_record of Metric.
Refactored Report specs. Also overrided == method for Metric and added test for it.
Surrounded contexts with describe with method name for Tariff specs.
Changed :truncation to :transaction for rspec. Specs now running much faster then before.
Added authentication requirement for SettingsController.
Fixed specs for #previous_metric. Problem was with a uncontrolled FactoryGirl sequence counter for metric month sequence.
Fixed a problem with metric counter equality check. Replaced with in_delta comparison.