Correct a few typos and remove nan workaround

Constraints was misspelled, however the default value would work fine if
instance_type wasn't specified. The list syntax for HOT was also
incorrect.

There was a dependency problem that is fixed now, so force installing
nodejs-bson is no longer required.

Change-Id: Iabc9ff4be7cfa479d6cf11f735857f16b3de4905
Merge "Correct a few typos and remove nan workaround"