Option to disable SSL Certificate verification

[santhoshramaraj]

In some scenarios, the SystemLink instance may not have a verifiable SSL certificate, such as one generated by a private CA. In this scenario, SSL verification is expected to fail without adding the certificate as trusted. It will be good to have the ability to disable the verification to allow users to override the verification.

# Example to disable SSL verify using requests
# Set `verify=False` on `requests.post`.
requests.post(url='https://example.com', data={'bar':'baz'}, verify=False)

[rbell517]

Uplink supports this by providing a custom requests session to the base Consumer class all of our clients are based on.

With this in mind we have two options. We can expose a standard **kwargs argument to our client constructors that we forward down to the Consumer constructor, which will allow anyone to make a customer session and set it's verify to false, along with anything else they might want to do with the Consumer constructor. That is more flexible for future needs that might want access to the underlying uplink capabilities and is a fairly standard practice in Python. As the uplink docs note, this same approach could be used to provide a requests session subclass or to switch to an async client, for example.

session = requests.Session()
session.verify = false
client = TestMonitorClient(client = session)

The other option is to add a verify field to the HttpConfiguration all clients already accept, and if it is set BaseClient would make the custom session as above. That is more explicit and relies less on understanding the inner working of the uplink library but its worth noting that the verify option is not present on the SL Client's persisted HTTP configuration files that our HttpConfiguration represents so we'd be getting a bit of out step there.

http_configuration = core.HttpConfigurationManager.get_configuration()
http_configurtion.verify = False
client = TestMonitorClient(http_configuration)

I lean toward the second approach as its a better fit with what we've been doing to minimize uplink's exposure on our clients.