Updated readWriteTransaction to fix bug (#317)
Updated readWriteTransaction to fix bug (#317)

* Updated readWriteTransaction to fix bug

Documentation at https://cloud.google.com/spanner/docs/transactions#rw_transaction_example says that second budget should be at least $300,000 for the transaction to proceed. I'm fixing this for Python / Node. Addresses bug #35360945.

* Moved 300000 to minimumAmountToTransfer constant

as per code review

thesandlord/nodejs-docs-samples,JustinBeckwith/nodejs-docs-samples,GoogleCloudPlatform/nodejs-docs-samples,thesandlord/nodejs-docs-samples,GoogleCloudPlatform/nodejs-docs-samples,GoogleCloudPlatform/nodejs-docs-samples,srijangulati/sierracartel,srijangulati/sierracartel,GoogleCloudPlatform/nodejs-docs-samples,JustinBeckwith/nodejs-docs-samples,JustinBeckwith/nodejs-docs-samples,srijangulati/sierracartel