Unable to update the git submodules

[JR40159]

After the cloning the repository, running git submodule update --init as documented in the README fails due to network timeout.

Submodule 'test/suite' (git://github.com/json-schema-org/JSON-Schema-Test-Suite.git) registered for path 'test/suite'
Cloning into '/xxx/xxx/xxx/jsonschema/test/suite'...
fatal: unable to connect to github.com:
github.com[0: 140.82.121.3]: errno=Connection timed out

This means that the library cannot be installed via npm using the github URL because npm clones the repository and resolves submodules.

[henryrgithub]

I had this issue when I had cloned the repo via HTTPS, but the submodule link in .gitmodules was GIT syntax.

You might have luck either cloning the repo over SSH (using the GIT link) or changing the link in the .gitmodules file to https://

A PR #396 has since been merged that includes the change to the .gitmodules link, so you could pull latest and then the update should just work.