Adding support for vpcConnector when deploying a function

[idoshilon]

Adding support to set vpcConnector when deploying a function (i.e if you want to access memory store form cloud function).
See here - https://cloud.google.com/functions/docs/networking/connecting-vpc?authuser=1

I think it should be done around this area -

serverless-google-cloudfunctions/package/lib/compileFunctions.js

Line 27 in 9bc2237

const funcTemplate = getFunctionTemplate(

adding support for vpcConnector and vpcConnectorEgressSettings.

[medikoo]

@idoshilon thanks for report. PR is welcome!

[idoshilon]

actually, I missed it but I think it was added - #191