Include missing scenario in test plan and fix typos

[fernandopradocabrillo]

What type of PR is this?

Add one of the following kinds:

• correction
• enhancement/feature
• tests

What this PR does / why we need it:

Include:

1. a missing test for check operation when there has not been a device swap withing the allowed monitored period
2. a missing test when the maxAge requested is above the allowed monitored period
3. a new step to retireveDate test for the optional returning of the monitoredPeriod variable
4. fix a couple of typos

Which issue(s) this PR fixes:

Fixes #73

[albertoramosmonagas]

All good, but I would like to add a few comments:

• Units: the tests mix hours (default maxAge 240 hours) with monitoredPeriod described in days. It would be better to standardize or explicitly clarify both units in each assert.
• And I would suggest adding 3 more tests:

@check_device_swap_8_connected_no_swap
/check – Connected without swap (ever):
Then 200 and body {“swapped”: false, “monitoredPeriod”: <value>}.

@retrieve_device_swap_7_connected_no_swap
/retrieve-date – Connected without swap (ever):
Variant A: {“latestDeviceChange”: “<activationDate>”}
Variant B (if policy does not allow date): {“latestDeviceChange”: null, “monitoredPeriod”: <value>}.

@check_device_swap_9_first_installation_is_swap
/check – First installation within period:
Then 200 and body {“swapped”: true, “monitoredPeriod”: <value>}.

[fernandopradocabrillo]

• Units: the tests mix hours (default maxAge 240 hours) with monitoredPeriod described in days. It would be better to standardize or explicitly clarify both units in each assert.

thanks @albertoramosmonagas for the comments, I have updated accordingly

[bigludo7]

Thanks @fernandopradocabrillo and @albertoramosmonagas for additional cases.