add has_many :post to Board
add bcrypt gem for ActiveModel::SecurePassword
rename password columns
remove critical bug
introduce sample data
fix README.md
Simplify size_for_print
Update README.md
Fix RuboCop offences and regenerate todo
Move extension of String to core_ext
Merge pull request #12 from yous/patch-develop

Move core extensions to `core_ext`
Add .rake files to RuboCop
Merge pull request #13 from yous/patch-rubocop

Add .rake files to RuboCop
Add an index on name column of Board

ea5383016a318092920931c6e3e49964fa36956f actually didn't add an index on
name.
Avoid using class variables
Replace verbose unless nil check statements with if
Use bang methods to change content of the object
Exclude generated files from RuboCop
Merge pull request #14 from yous/patch-rubocop

Progress
Merge pull request #16 from yous/patch-board-index

Add an index on name column of Board