Organisation should be called Organization

[kedare]

Describe the bug
All the references to Organization are called Organisation in the code, this is not correct.

To Reproduce
Steps to reproduce the behavior:

grafana = grafana_api.GrafanaFace(
    host=GRAFANA_HOST,
    auth=GRAFANA_KEY,
    protocol="https",
    port=443
)

log.debug(grafana.organization)

Expected behavior
Organization API should be returned instead of None

Versions

• Grafana: [ 6.0.0 ]
• grafana_api: [ grafana-api==0.5.2 ]
• Authentication: [Token]

[svet-b]

This change should also be applied to the other sub-modules with similarly named functions, e.g. user currently has get_user_organisations(), switch_user_organisation(), switch_actual_user_organisation, and get_actual_user_organisations.

Under the current situation I need to keep checking the source code for this module in order to work out whether I should be calling it "organization" or "organisation", depending on which specific function I'm calling...