Go: handle version like beta1

[mtanda]

Description:
sam build is failed with go1.15beta1.

$ go version
go version go1.15beta1 linux/amd64

Steps to reproduce the issue:

1. install go1.15beta1
2. execute sam build

Observed result:
Get error.

    version_parts = [int(x.replace("rc", "")) for x in out_parts[2].replace(self.LANGUAGE, "").split(".")]
ValueError: invalid literal for int() with base 10: '15beta1'

Expected result:
No error.

Additional environment details (Ex: Windows, Mac, Amazon Linux etc)
Ubuntu 18.04 (Windows/WSL)

[mtanda]

I think, validator need to remove string like beta.* in https://github.com/awslabs/aws-lambda-builders/blob/v1.0.0/aws_lambda_builders/workflows/go_modules/validator.py#L50

[hoffa]

Closing; resolved in 1.7.0.