Attempt to fix circle. - update to node 10 - set maxWorkers on unittests so they don't spawn so many that we run  out of memory. - set runInBand on integration tests. There's a weird interaction that  makes the constumes test or tutorials test fail due to a page crash.
Attempt to fix circle.
- update to node 10
- set maxWorkers on unittests so they don't spawn so many that we run 
out of memory.
- set runInBand on integration tests. There's a weird interaction that 
makes the constumes test or tutorials test fail due to a page crash.

LLK/scratch-gui,LLK/scratch-gui