Remove foreman gem

foreman depends on a thor version that is incompatible with
Rails 6. We also don't need this because old GDK installs its
own foreman gem and new versions use RUnit now.

It is also not recommended to bundle foreman:
https://github.com/ddollar/foreman/wiki/Don't-Bundle-Foreman

Gemfile

@@ -331,7 +331,6 @@ group :metrics do
 end
 
 group :development do
-  gem 'foreman', '~> 0.84.0'
   gem 'brakeman', '~> 4.2', require: false
   gem 'danger', '~> 6.0', require: false
 

Gemfile.lock

@@ -334,8 +334,6 @@ GEM
       nokogiri (>= 1.5.11, < 2.0.0)
     font-awesome-rails (4.7.0.4)
       railties (>= 3.2, < 6.0)
-    foreman (0.84.0)
-      thor (~> 0.19.1)
     formatador (0.2.5)
     fugit (1.2.1)
       et-orbi (~> 1.1, >= 1.1.8)
@@ -1161,7 +1159,6 @@ DEPENDENCIES
   fog-openstack (~> 1.0)
   fog-rackspace (~> 0.1.1)
   font-awesome-rails (~> 4.7)
-  foreman (~> 0.84.0)
   fugit (~> 1.2.1)
   fuubar (~> 2.2.0)
   gemojione (~> 3.3)