do not change pwd after exiting Pluto

[Roger-luo]

I find currently Pluto is using cd directly instead of use it as a context.

https://github.com/fonsp/Pluto.jl/blob/master/src/evaluation/WorkspaceManager.jl#L62

this changes the results of pwd() and can cause problems when someone tries to start pluto inside a script (e.g managing pluto instances)

[fonsp]

It only cds within the notebook process, right?

[Roger-luo]

for this line, I think yes. But I think this somehow affects the main process, when you

1. execute Pluto.run
2. then open a new notebook (don't save it)
3. then Ctrl+C in terminal
4. pwd() will be moved to the tempdir

[Roger-luo]

this should be fixed in #367