evaluator fails on windows file paths

[meier-christoph]

When using commands that require evaluation with an EvalScript e.g. tk diff default --name foo on windows you get an error due to the file path separator.

Error: evaluating jsonnet: default:2:24-98 Unknown escape sequence in string literal: \g
  local main = (import 'C:\<path to project>\environments\default\main.jsonnet');

See: https://github.com/grafana/tanka/blob/master/pkg/tanka/evaluators.go#L27

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[Duologic]

/keepalive

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.