##### SUMMARY
`ansible-galaxy collection install` currently requires the user to specify an install path using the `-p` option. Galaxy currently generates and displays the CLI command for installing a collection. There is no way for Galaxy to determine a value for `-p`, and hard coding a default value into Galaxy makes no sense.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
`ansible-galaxy`

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```
ansible 2.10.0.dev0
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/Users/chouseknecht/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /Users/chouseknecht/projects/ansible/lib/ansible
  executable location = /Users/chouseknecht/.pyenv/versions/venv27/bin/ansible
  python version = 2.7.14 (default, Nov 14 2017, 23:24:24) [GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.38)]
```

"""
        lists the roles installed on the local system or matches a single role passed as an argument.
        """
        def _display_role(gr):
            install_info = gr.install_info
            version = None
            if install_info:
                version = install_info.get("version", None)
            if not version:
                version = "(unknown version)"
            display.display("- %s, %s" % (gr.name, version))
        if context.CLIARGS['role']:
            
            name = context.CLIARGS['role']
            gr = GalaxyRole(self.galaxy, self.api, name)
            if gr.metadata:
                display.display('# %s' % os.path.dirname(gr.path))
                _display_role(gr)
            else:
                display.display("- the role %s was not found" % name)
        else:
            
            roles_path = context.CLIARGS['roles_path']
            path_found = False