Support tags

[svroonland]

Would be great to support adding tags to created alerts.

[jonboydell]

Note - from the swagger docs - https://github.com/logzio/public-api/blob/master/alerts/swagger.json - isn't in the example on the API page

"tags" : {
    "type" : "array",
    "items" : {
        "type" : "string"
     },
    "maxItems" : 10,
    "minItems" : 0
},

[yyyogev]

Done at #43