error in __extract_dependencies()

[justinmk2]

At d7e39f0, running :

./license-cop https://github.com/foo report.txt

Some python repositories provoke this error:

--> Resolving Python dependencies (will take a while...)
Traceback (most recent call last):                                    
  File "/home/jkeyes/license-cop/app/main.py", line 91, in process_repositories
    process_repository(repo, report)        
  File "/home/jkeyes/license-cop/app/main.py", line 51, in process_repository
    report.process(match)                 
  File "/home/jkeyes/license-cop/app/reporting/report.py", line 10, in process
    for i in match.resolve(self._max_depth):
  File "/home/jkeyes/license-cop/app/platform.py", line 19, in resolve        
    self.__cache[max_depth] = self.platform.resolve(self, max_depth)
  File "/home/jkeyes/license-cop/app/platform.py", line 42, in resolve
    return [self.__resolve_manifest(i, max_depth) for i in match.manifests]
  File "/home/jkeyes/license-cop/app/platform.py", line 42, in <listcomp>
    return [self.__resolve_manifest(i, max_depth) for i in match.manifests]
  File "/home/jkeyes/license-cop/app/platform.py", line 48, in __resolve_manifest
    root.add_children(self.__resolve_dependencies(resolver, max_depth, manifest.runtime_dependencies))
  File "/home/jkeyes/license-cop/app/dependency_resolution.py", line 79, in add_children
    for i in children:                      
  File "/home/jkeyes/license-cop/app/platform.py", line 54, in <genexpr>
    return (resolver.resolve(i, max_depth) for i in dependencies)
  File "/home/jkeyes/license-cop/app/dependency_resolver.py", line 12, in resolve
    root = self.__build_node(dependency)
  File "/home/jkeyes/license-cop/app/dependency_resolver.py", line 48, in __build_node
    version = self.__fetch_version(dependency)        
  File "/home/jkeyes/license-cop/app/dependency_resolver.py", line 57, in __fetch_version
    return self.__registry.fetch_latest_version(dependency.name)
  File "/home/jkeyes/license-cop/app/package_registry.py", line 52, in fetch_latest_version
    return self.__cached_fetch(id, self._fetch_latest_version)
  File "/home/jkeyes/license-cop/app/package_registry.py", line 57, in __cached_fetch
    return self.__cache_miss(id, fetch_function)                                
  File "/home/jkeyes/license-cop/app/package_registry.py", line 62, in __cache_miss
    version = fetch_function(*id)           
  File "/home/jkeyes/license-cop/app/platforms/python/package_registry.py", line 61, in _fetch_latest_version
    return self.__build_package(response.json())
  File "/home/jkeyes/license-cop/app/platforms/python/package_registry.py", line 72, in __build_package
    deps = self.__extract_dependencies(info)
  File "/home/jkeyes/license-cop/app/platforms/python/package_registry.py", line 65, in __extract_dependencies
    return [parse_dependency(i) for i in requires_dist]
TypeError: 'NoneType' object is not iterable