Upgraded libraries

What's new in Version 2.0

Dependencies:

• removed package request-promise-native from dependencies (package was blocking upgrade of nano to version > 8.2.3)
• upgraded nano to version 10.0.0

Added db document functions:

• getDesign for getting all design and view documents,
• deleteDocumentsInBulk for deleting array of documents,
• fetchDocumentsInBulk for fetching array of documents,
• getViewWithQuery for getting view with different key options

Removed db document functions:

• getViewWithMultipleQueries: not needed anymore, replaced partially by getViewWithQuery

Modified db document functions:

• destroyDocument: revision parameter is optional,

Tests:

• added test for Node (no testing framework is required)