Make geolocalization disabled by default

[heitortsergent]

https://github.com/keenlabs/KeenClient-iOS/blob/master/KeenClient/KeenClient.m#L194

[terrhorn]

Documentation will need to be updated when this change occurs as it specifically states that Geo Location is enabled by default: https://github.com/keenlabs/KeenClient-iOS#geo-location

[terrhorn]

Concern: this is going to break existing implementations that don't explicitly enable Geo Location, perhaps unknowingly so. Do we have a good reason for disabling by default vs. enabling by default?

[heitortsergent]

I think there are a couple of good reasons why disabled by default is a better behavior:

1. That change means we are asking developers to be more conscious about their user's privacy, and explicit about needing location information.
2. It can save user's bandwidth (maybe it's negligible) and resources for Keen.

Yes, this will break existing implementations. I don't know if those 2 reasons are good enough taking that into account, and we would definitely need to notify the developers that use this SDK, and maybe give a timeline of when this will be merged. But I think we should make that change eventually.

[terrhorn]

The challenge in notifying those who use this particular SDK is that none of our SDKs currently include any data that would allow us to discern one SDK from another. We should leave this PR open until we've added that capability.

[heitortsergent]

Ok, sounds good 👍 . I'll open a separate issue for adding that capability.

[baumatron]

#173 has been completed, so this should be good to go in. Does seem like it is a breaking change, so maybe should be slated for major release.