Add remote atlas fetching and version comparison functionalities
to the core Atlas class.
​
Parameters
----------
atlas_name : str
    Name of the atlas to be used.
brainglobe_dir : str or Path object
    Default folder for brainglobe downloads.
interm_download_dir : str or Path object
    Folder to download the compressed file for extraction.
check_latest : bool (optional)
    If true, check if we have the most recent atlas (default=True). Set
    this to False to avoid waiting for remote server response on atlas
    instantiation and to suppress warnings.
print_authors : bool (optional)
    If true, disable default listing of the atlas reference.

def __init__(self, atlas_name, brainglobe_dir=None,
    interm_download_dir=None, check_latest=True, print_authors=True):

def local_version(self):

If atlas is local, return actual version of the downloaded files;
​
Else, return none.

def remote_version(self):

Remote version read from GIN conf file. If we are offline, return
​
None.

def local_full_name(self):

As we can't know the local version a priori, search candidate dirs
​
using name and not version number. If none is found, return None.

def remote_url(self):

Format complete url for download.

def download_extract_file(self):

Download and extract atlas from remote url.

def check_latest_version(self):

Checks if the local version is the latest available
​
and prompts the user to update if not.

def __repr__(self):

Fancy print for the atlas providing authors information.

def _version_tuple_from_str(version_str):

def _version_str_from_tuple(version_tuple):