Missing `graphql` dependency in iExec CLI tutorial setup

[ngjupeng]

Hello iExec team!

I encountered an issue while following the tutorial here.

When running the setup, I received the following error message:

Cannot find package 'graphql'

I had to manually install graphql to proceed by running npm i -g graphql. It seems the package might be missing from the dependencies of the CLI tool.

Just wanted to flag this in case it needs to be added to the project dependencies.