(PUP-772) Add the install_option attribute to the apt provider

Since the package provider install_option attribute exists I, have
added it to the apt provider. With this (4 line) patch the apt provider
becomes much more flexible and it will prevent 'hacks' and work
arounds in Puppet code for Debian machines.

Example use case:
When you use Percona SQL instead of MySQL it becomes hard to not
overwite the percona packages with the regular MySQL packages.

The problem:
  sudo apt-get install percona-server-server-5.5
  sudo apt-get install zabbix-server-mysql

The thing which is gonna happen now is that the zabbix-server-mysql
will replace percona-server-server-5.5 with mysql-server because
it is in the recommends of the zabbix-server-mysql package.

The solution:
  sudo apt-get install percona-server-server-5.5
  sudo apt-get --no-install-recommends install zabbix-server-mysql

Unfortunately specifying this option is not possible in Puppet.
With this patch it does, and it solves way more issues you can
have with apt and Puppet, for example feature request: #2406.

Example Puppet code:

  package { 'zabbix-server-mysql':
    ensure          => present,
    install_options => '--no-install-recommends';
  }

  package { 'zabbix-server-mysql':
    ensure          => present,
    install_options => ['--no-install-recommends', '--install-suggests'];
  }
(PUP-772) Fix apt provider install_options

Fix apt package provider install options to support hash in addition to
arrays and strings.  This makes it consistent with other package
providers.

Add spec examples to test install options.
(PUP-772) Fix apt package provider spec for install_options.

Fixing the apt package provider spec so that the resource isn't entirely
mocked and returning 'asdf' for every property. Modeling the spec after
the yum package provider spec to accomplish that.

Adding install_option example that tests for hash.
Merge branch 'pr/2082'

* pr/2082:
  (PUP-772) Fix apt package provider spec for install_options.
  (PUP-772) Fix apt provider install_options
  (PUP-772) Add the install_option attribute to the apt provider

This closes GH-2082.