Setup MongoDB & Express

[JudeShamsi]

User Story

Add the user story number here. Feat/IN-55: https://chaosneutral.atlassian.net/jira/software/projects/IN/boards/1?selectedIssue=IN-55

Changes made

Describe the changes made in this PR.

• installed express app, mongoose, body-parser, concurrently, nodemon
• connected mongodb to application
• created express backend applicaiton and setup backend server
• created jobposting routes GET, POST, DELETE and verified functionality via Postman
• created JobPostingData model and connected to APIs (verified functionality via Postman)
• IMPORTANT: the new way to run both front-end and backend servers (THIS MUST BE IN THE CLIENT SIDE, NOT BACKEND SIDE) is 'npm run dev'

Does your new code introduce new warnings on dev console?

Yes/No. No

Test Steps

Describe the test steps to test your changes. Verified via Postman

[tommytwm]

Could you describe sometime in the future how we are to test these changes? Like you mentioned tested in postman but I'm unsure what endpoints we should be hitting and what kinds of results we are expecting back, for example.