Add `apiSupported` property

[FluorescentHallucinogen]

• Add apiSupported property that indicates whether Geolocation API is supported or not.
• Update code and descriptions of samples in geo-location.html, demo/index.html and README.md files.
• Remove version field in bower.json file, because it's deprecated and ignored by Bower (https://github.com/bower/spec/blob/master/json.md#version).
• Add polymer-element, polymer-2 and polymer-2-hybrid keywords to bower.json file to indicate that this is Polymer 1.x/2.x hybrid element.

[FluorescentHallucinogen]

@ebidel PTAL.

[ebidel]

Please add a test.

[FluorescentHallucinogen]

@ebidel

Please add a test.

What do you mean?

[ebidel]

Add a test case: https://github.com/ebidel/geo-location/tree/master/test