Increase PipeCleaner timeout to 5 seconds
Increase PipeCleaner timeout to 5 seconds

We sometimes see test timeouts on Travis:

```
• Failure in Spec Setup (JustBeforeEach) [2.001 seconds]
PipeCleaner
/home/travis/gopath/src/github.com/alphagov/paas-cf/concourse/scripts/pipecleaner_test.go:13
  shellcheck [JustBeforeEach]
  /home/travis/gopath/src/github.com/alphagov/paas-cf/concourse/scripts/pipecleaner_test.go:40
    disabled
    /home/travis/gopath/src/github.com/alphagov/paas-cf/concourse/scripts/pipecleaner_test.go:41
      should not report anything
      /home/travis/gopath/src/github.com/alphagov/paas-cf/concourse/scripts/pipecleaner_test.go:46
      Timed out after 2.000s.
      Expected process to exit.  It did not.
```

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf