Version Bump v4.7.1: sendgrid#329 Simplify installation instructions

Version Bump v4.7.0: Pull sendgrid#323, Fixed issue sendgrid#317: Inv…

…oke the API callback with a mocked response upon Error

Version Bump v4.6.0: Pull sendgrid#319, Fixed issue sendgrid#266 Conv…

…erts response.body to have valid json objects

Version Bump v4.5.0: feat: Add support for promises to the TypeScript…

… definitions file

Version Bump v4.4.1: Pull sendgrid#309 Allow emptyRequest() to be cal…

…led with a request object

Version Bump v2.4.0: sendgrid#299 Fill 'response' property in error i…

…nstance

Merge branch 'master' of https://github.com/sendgrid/sendgrid-nodejs

Version Bump v4.3.0: Pull sendgrid#251 - Typescript

Version Bump v4.2.1: Fix Issue sendgrid#292 - debug depedency

Version Bump v4.2.0: Pull Request sendgrid#278: contact importer