Update acceptance test to reflect Project rename bugfix with go-tfe v1.16.0 upgrade

[sebasslash]

Description

The title is a concise summary 📖 and this PR closes #714

The fix was actually implemented in our go-tfe dependency here (released in v1.16).

The go-tfe library was validating project names as external IDs, of which inner spaces would result in a validation error. go-tfe was upgraded here.

I've updated the tfe_project resource Update test and changed the name attribute to include an inner space to reflect the fix 😄

Testing plan

Acceptance Test

ENABLE_BETA=1 TESTARGS="-run TestAccTFEProject_update" make testacc

Smoke Test

1. Apply this config:

resource "tfe_project" "foo" {
  name = "a project name with spaces"
  organization = "<my_org_name>"
}