Prawn gem error


I want to use Dradis to CentOS 7.0 but I’ve an error to prawn gem version.

Gem list : Prawn 2.1.0

I’ve this issue with setup bin/setup:

== Installing dependencies ==
The git source git:// is not yet checked out. Please run `bundle install` before trying to start your application
Fetching git://
Fetching git://
Fetching git://
Fetching git://
Resolving dependencies...
Some gems seem to be missing from your vendor/cache directory.
Bundler could not find compatible versions for gem "prawn":
  In Gemfile:
    dradis-pdf_export was resolved to 3.2.1, which depends on
      prawn (~> 0.15.0)

Could not find gem 'prawn (~> 0.15.0)', which is required by gem 'dradis-pdf_export', in any of the sources.

Do you have a solution ?