README.md: added reminder to generate model and apply migrations
Add an argument which can define prefix name

add an command argument named —prefix_name=“xxxx”
correct  option name of prefix_name
test of prefix_name option
Change Readme
Merge branch 'master' into develop
Merge branch 'master' of github.com:zmbacker/rails-admin-scaffold into zmbacker-master
Merge branch 'zmbacker-master' into develop
Rails version support updated, docs updated
Travis badge set to develop for develop branch
TestUnit replaced with minitest
travis badge for master branch