test(sessions): move session unit tests to new unit tld

NODE-1088

package.json

@@ -45,7 +45,7 @@
     "url": "https://github.com/mongodb/node-mongodb-native/issues"
   },
   "scripts": {
-    "test": "mongodb-test-runner -t 60000 test/functional",
+    "test": "mongodb-test-runner -t 60000 test/unit test/functional",
     "coverage": "node_modules/.bin/nyc node test/runner.js -t functional && node_modules/.bin/nyc report --reporter=text-lcov | node_modules/.bin/coveralls",
     "lint": "eslint lib test",
     "format": "prettier --print-width 100 --tab-width 2 --single-quote --write 'test/**/*.js' 'lib/**/*.js'"

test/functional/sessions_tests.js → test/unit/sessions/client_tests.js

@@ -1,13 +1,13 @@
 'use strict';
 
-const MongoClient = require('../..').MongoClient;
+const MongoClient = require('../../..').MongoClient;
 const expect = require('chai').expect;
-const assign = require('../../lib/utils').assign;
-const mock = require('../mock');
+const assign = require('../../../lib/utils').assign;
+const mock = require('../../mock');
 
 const test = {};
 describe('Sessions', function() {
-  describe('unit', function() {
+  describe('Client', function() {
     afterEach(() => mock.cleanup());
     beforeEach(() => {
       return mock.createServer().then(server => {