[DRE-maint] Bug#945481: Bump minimum version of ruby-molinillo dependency in ruby-bundler

[Pirate Praveen]

Package: bundler
Version: 1.17.3-3
Severity: serious

While upgrading from stretch to buster I noticed this error with 
bundler and bundler command failed.

NoMethodError: undefined method `message_with_trees' for 
#<Molinillo::VersionConflict:0x0000559d95ce0698>

This was resolved by updating ruby-molinillo from buster.

Currently ruby-bundler declares ruby-molinillo (>= 0.4.5~) it should be 
updated to >= 0.6~

# Error Report

## Questions

Please fill out answers to these questions, it'll help us figure out
why things are going wrong.

- **What did you do?**

  I ran the command `/usr/bin/bundle --local --quiet`

- **What did you expect to happen?**

  I expected Bundler to...

- **What happened instead?**

  Instead, what happened was...

- **Have you tried any solutions posted on similar issues in our issue 
tracker, stack overflow, or google?**

  I tried...

- **Have you read our issues document, 
https://github.com/bundler/bundler/blob/master/doc/contributing/ISSUES.md?**

  ...

## Backtrace

```
NoMethodError: undefined method `message_with_trees' for 
#<Molinillo::VersionConflict:0x0000559d95ce0698>
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/resolver.rb:303:in 
`version_conflict_message'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/resolver.rb:55:in 
`rescue in start'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/resolver.rb:45:in 
`start'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/resolver.rb:22:in 
`resolve'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/definition.rb:258:in 
`resolve'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/definition.rb:170:in 
`specs'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/definition.rb:151:in 
`resolve_with_cache!'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/installer.rb:310:in 
`resolve_if_needed'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/installer.rb:84:in 
`block in run'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/process_lock.rb:12:in 
`block in lock'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/process_lock.rb:9:in 
`open'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/process_lock.rb:9:in 
`lock'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/installer.rb:73:in 
`run'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/installer.rb:25:in 
`install'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/cli/install.rb:65:in 
`run'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/cli.rb:235:in 
`block in install'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/settings.rb:143:in 
`temporary'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/cli.rb:234:in 
`install'
  /usr/lib/ruby/vendor_ruby/thor/command.rb:27:in `run'
  /usr/lib/ruby/vendor_ruby/thor/invocation.rb:126:in `invoke_command'
  /usr/lib/ruby/vendor_ruby/thor.rb:369:in `dispatch'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/cli.rb:27:in 
`dispatch'
  /usr/lib/ruby/vendor_ruby/thor/base.rb:444:in `start'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/cli.rb:18:in 
`start'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/exe/bundle:30:in 
`block in <top (required)>'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/lib/bundler/friendly_errors.rb:124:in 
`with_friendly_errors'
  
/usr/share/rubygems-integration/all/gems/bundler-1.17.3/exe/bundle:22:in 
`<top (required)>'
  /usr/bin/bundle:23:in `load'
  /usr/bin/bundle:23:in `<main>'
```

## Environment

```
Bundler 1.17.3
  Platforms ruby, x86_64-linux
Ruby 2.5.5p157 (2019-03-15 revision 67260) [x86_64-linux-gnu]
  Full Path /usr/bin/ruby2.5
  Config Dir /etc
RubyGems 2.7.6.2
  Gem Home /var/lib/gitlab/.gem
  Gem Path 
/var/lib/gitlab/.gem/ruby/2.5.0:/var/lib/gems/2.5.0:/usr/lib/x86_64-linux-gnu/rubygems-integration/2.5.0:/usr/share/rubygems-integration/2.5.0:/usr/share/rubygems-integration/all:/var/lib/gitlab/.gem
  User Path /var/lib/gitlab/.gem/ruby/2.5.0
  Bin Dir /var/lib/gitlab/.gem/bin
OpenSSL
  Compiled OpenSSL 1.1.1c 28 May 2019
  Loaded OpenSSL 1.1.1d 10 Sep 2019
  Cert File /usr/lib/ssl/cert.pem
  Cert Dir /usr/lib/ssl/certs
Tools
  Git 2.20.1
  RVM not installed
  rbenv not installed
  chruby not installed
Gem.ruby /usr/bin/ruby2.5
bundle #! /usr/bin/ruby

```

## Bundler Build Metadata

```
Built At 2018-12-27
Git SHA d7089abb6
Released Version true
```

## Bundler settings

```
without
  Set for your local app (/usr/share/gitlab/.bundle/config): 
[:development, :test]
  Set for the current user (/var/lib/gitlab/.bundle/config): 
[:development, :test]
```