Update Karma Config

When trying to run tests with `grunt karma` the following errors were occurring.

    Running "karma:unit" (karma) task
    WARN [config]: JASMINE is not supported anymore.
        Please use `frameworks = ["jasmine"];` instead.
    WARN [config]: JASMINE_ADAPTER is not supported anymore.
        Please use `frameworks = ["jasmine"];` instead.
    WARN [config]: LOG_INFO is not supported anymore.
        Please use `karma.LOG_INFO` instead.
    ERROR [config]: Config file must export a function!
        module.exports = function(config) {
            config.set({
                 // your config
            });
        };

Through a bit of investigation it seems that the Karma config file is no longer in the required format. I updated the config to export a function and also set up `frameworks = ["jasmine"]`.

Within this PR, I also updated a minor issue in one of the tests which was checking initial zoom level which changed in 5ad10df33fc21bb1210734b6064ecbb817706ba8

I'm 95% certain these changes needed to be made. :)