##### 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)]
```

if "include" not in requirement:
                role = RoleRequirement.role_yaml_parse(requirement)
                display.vvv("found role %s in yaml file" % to_text(role))
                if "name" not in role and "src" not in role:
                    raise AnsibleError("Must specify name or src for role")
                return [GalaxyRole(self.galaxy, self.api, **role)]
            else:
                b_include_path = to_bytes(requirement["include"], errors="surrogate_or_strict")
                if not os.path.isfile(b_include_path):
                    raise AnsibleError("Failed to find include requirements file '%s' in '%s'"
                                       % (to_native(b_include_path), to_native(requirements_file)))
                with open(b_include_path, 'rb') as f_include:
                    try:
                        return [GalaxyRole(self.galaxy, self.api, **r) for r in
                                (RoleRequirement.role_yaml_parse(i) for i in yaml.safe_load(f_include))]
                    except Exception as e:
                        raise AnsibleError("Unable to load data from include requirements file: %s %s"
                                           % (to_native(requirements_file), to_native(e)))
        if isinstance(file_requirements, list):
            
            if not allow_old_format: