add spreadsheet parser and fix event.csv
refactor specs and assets, use SpreadsheetParser
refactor specs and assets, use SpreadsheetParser
Merge branch 'simple_import' of github.com:blan4/SummaryApp into simple_import
Merge branch 'master' into simple_import
spreadsheet validation finaly works. add test and functions to models
add validation on participants in spreadsheet and beauty error msgs