Add specs for sign up functionality in development environment
Add uniq constraint to User accordance with DB schema
Create routes to create user when development environment
Add link to user#new in development environment
Add /user/new page
Allow developer stragety in test environment

To test "sign in with developer strategy."
Show error messages for number_field
Add user#create functionality
Add spec for UserContext
Change notation of Hash
Fix validation for user.uid after composite key constraint
Merge pull request #66 from KitaitiMakoto/dev-signup

Dev signup