Hello,
I think you can consider those tools:
1. source code repository: github or bitbucket
2. bug tracking & work assignment, issue tracking, burndown report...: you can you Jira, < 10 people you just need to spend 10$/month.
3. Build & deploy (CI): I used nodejs as side project as my hobby, so never consider it before:), google with keyword "CI for MEAN/nodejs" can bring up some ideas. If you use some cloude services such as Heroku, they come along with their own toolkit to help you deploy on the air.
4. Testing framwork: Chai, Mocha