Add e2e test for voting

- Log in as admin
- Create 100 tokens
- Activate 3 tokens
- Create voting
- Add 2 candidates
- Repeat for each token
  - Log in with token
  - View voting
  - Vote for first candidate
  - Expect vote to have been cast
- Return to admin account
- Expect all tokens to have voted
- Close voting
- Expect first candidate to be the winner