Add missing fields to IEXCompany

[juancarlosqr]

Changes

• Resolves Missing types from Company interface for typescript #37:
  • Add missing types to IEXCompany
  • Create a separate Company.test.ts file for the Company service

Notes

Hi @schardtbc! I'm adding this as part of the Hacktoberfest effort 🍻🥨. In order for this PR to be accepted for the Hacktoberfest you would have to add the designated label:

An individual PR can be opted-in with a maintainer adding the "hacktoberfest-accepted" label to the PR.

If you can do that, I would highly appreciate it! 🤞🏼 Thanks

[juancarlosqr]

@schardtbc You got a new PR!