Switch from jasmine to mocha + expect + lolex

Much of this transformation has been done automatically:
 * add expect import to each file
 * replace `not.to` with `toNot`
 * replace `to[Not]Be{Undefined,Null}` with equivalents
 * replace `jasmine.createSpy(...)` with `except.createSpy`, and `andCallFake`
   with `andCall`

Also:
 * replace `jasmine.createSpyObj` with manual alternatives
 * replace `jasmine.Clock` with `lolex`

spec/unit/filter.spec.js

@@ -4,6 +4,8 @@ const sdk = require("../..");
 const Filter = sdk.Filter;
 const utils = require("../test-utils");
 
+import expect from 'expect';
+
 describe("Filter", function() {
     const filterId = "f1lt3ring15g00d4ursoul";
     const userId = "@sir_arthur_david:humming.tiger";