Add tests for arcgis js api 3.x.

[cancastilho]

Adds configuration for running tests for arcgis js api 3.x.
Tests in wicket-arcgis3-amd-spec.js file were created based on tests from wicket-gmap3-spec.js.

To run the tests execute:

npm install
karma start karma.arcgis3.conf.js

It was necessary to put karma config in another config file to prevent conflict with google maps tests.

Interesting enough, some tests that works for google maps, won't work for arcgis. See the results below:

Standard Arcgis 3 WKT Test Cases:
√ should convert a Esri Point into a basic POINT string
√ should convert a Esri Polyline instance into a basic LINESTRING string
√ should convert a Esri Polygon instance into a basic POLYGON string
√ should convert an Esri Multipoint instances into a MULTIPOINT string
× should convert an Array of Esri Polyline instances into a MULTILINESTRING string
× should convert an Array of Esri Polygon instances into a MULTIPOLYGON string
√ should convert a Esri Polygon instance with a hole into a POLYGON string with the same hole
× should convert an Array of Esri Polygon instances, some with holes, into a MULTIPOLYGON string with the same hole