Create firebase project + database

[hilzfa]

Hint: Creation of database is probably blocked by #5

Acceptance criteria:

• [ ] Clarify which technology to use: SDK in script or npm package
• [ ] Firebase SDK or npm package is added to the project
• [ ] firebase CLI tools are added to package.json

[derpfeifenmarcel]

Firebase SDK needs to be added to the project. We have at least two options for that:

• using the following code snippet:

- using a ionic/react npm package (my suggestion>

next we have to install the CLI for firebase to the project
`npm install -g firebase-tools`