add text_banner column
migrate existing Banner feature to ImageBanner

changed namespace and class constant name
made specs work fine
updated test_app schema.rb
rename rest of files
added TextBanner scaffold_controller amd made them work
add preview action for text_banner
added text_banner.banner_text validation
remove a generated pending example
change column name from banner_text to text
change attribute names to refrect new column name
Merge pull request #1 from krayinc/text-banner

Text banner