Rename backers table to contributions
Rename backers files to contribution
Rename backer words to contribution
Rename more files to contribution
Fix migration name
Migrate backers to contributions on postgres views
Migrate notifications template name to contribution
Change notify_contributions to notify_contributors
Add migration to migrate user_total view to use contributions
Rename backs and backed to contributions
Solve conflits
Improve migration to change notifications template name
Rename backer reports to contribution reports
Rename backer_reports_for_project_owners view to contribution_reports_for_project_owners
Rename backers_by_periods view to contributions_by_periods
Adjust down migrations to use contributions table instead of backers
Remove unnecessary migration
Merge from master and solve conflits
Migrate lib tasks Backer to Contribution
Merge pull request #537 from josemarluedke/backer_to_contribution

Migrate Backer to Contribution