#167484557 Users should be able to share articles on social media and via email

[harerakalex]

What does this PR do?

• Users should be able to share articles on social media such as twitter and facebook and also via email.

Description of Task to be done?

• Add share article functionalities.
• Install react-share package

How should this be manually tested?

• Clone this branch
• npm install to install added package
• npm start to start the server
• Use this route http://localhost:3000/articles/:slug

What are the relevant pivotal tracker stories?

Users should be able to share articles on social media and via email

Any background context you want to provide?

• Share an article on facebook can't work when app is running locally (localhost).