MetricConfigurations cache on MezuroConfiguration's show #46.

Signed-off-by:Beatriz Rezener <beatrizrezener@gmail.com>
Signed-off-by:João Gabriel <joaogabrieldebrittoesilva@gmail.com>
Improving the solution #46
Merge pull request #150 from beatrizrezener/issue46

MetricConfigurations cache on MezuroConfiguration's show #46.
Add image for project
Fix broken tests

Signed-off-by: Vinicius Franco <viniciusf.arantes@gmail.com>
Signed-off-by: Thiago Ribeiro <thiagitosouza@hotmail.com>
 Refactored Project_controller.rb and project_image.rb
Fixed tests in project_controller.rb  and closes #25
Making suggested changes