Foursquare venue query node and tests (issue #42)

[hbeeken]

This node can be merged as it enables the user to explore "food", "outdoor venues" and "sights" near the provided location (lat/lon coordinates). It returns the first recommended venue from the ordered list as determined by Foursquare.

There are of course extensions which can be made (not limiting to 3 categories of venues, not limiting results returned to just the first recommended venue) but these can be done at a later time in other pull requests.

(Part of issue #42)

[coveralls]

Coverage increased (+3.6%) when pulling 716b5d9 on hbeeken:foursquare-venue-basic into b53844e on node-red:master.

[coveralls]

Coverage increased (+3.6%) when pulling 39a85f1 on hbeeken:foursquare-venue-basic into b53844e on node-red:master.

[knolleary]

The conclusion reached in node-red/node-red#399 is that if a property is set in the node, it cannot be overridden by the message. We obviously didn't do a good job communicating that around the team.

I'll review the other web nodes to make sure this is followed elsewhere.

[hbeeken]

Ah yes, I didn't appreciate that. I followed the behaviour in the weather node and this does the same thing:

    //if there is data in the message input, it overwrites the node setting values.
    //If the data is erroneous or not there, the values remain the node settings.

(weather.js line 20&21)

[zobalogh]

@knolleary Are you planning to include @hbeeken 's changes in the upcoming release too? Do you want me to move the location data under msg.location in this pull request as well? It's @hbeeken's work so I'd rather not touch it, especially as I'm not sure if I can somehow add changes on top of this pull request.

@hbeeken, depending on what @knolleary does, this pull request might need to be updated so that msg.lat, msg.lon is moved under a location object such as msg.location.lat, msg.location.lon.

[knolleary]

@zobalogh my comment here identified an issue with this PR that needs fixing before it can be merged. The lat/lon change can also be made along with that fix before I merge it.

Will hold the release to next week until this is done - no major urgency to have it done today.

[coveralls]

Coverage increased (+0.31%) when pulling d1900b6 on hbeeken:foursquare-venue-basic into 19b83c6 on node-red:master.

[hbeeken]

This change now includes both the updates to msg.location.lon/msg/location.lat as well as ensuring any node settings override those sent in the incoming msg. I believe it's ready to be merged.

Any updates returning multiple msgs etc. will be done as a separate pull request and build on this one.