refactored test suites

gulpfile.js

src/Database.js

src/Database.spec.js

src/Databases/IndexedDB.js

src/Databases/IndexedDB.spec.js

src/Databases/Memory.js

src/Databases/RedBlackTree.js

src/Databases/RedBlackTree.spec.js

src/Helper.spec.js

src/OperationStores/Memory.spec.js

src/Transaction.js