read the CI timescale factor from an environment variable

.travis.yml

@@ -14,6 +14,9 @@ go:
 # setting the GOARCH directly doesn't work, since the value will be overwritten later
 # so set it to a temporary environment variable first
 env:
+  global:
+    - TIMESCALE_FACTOR=20
+  matrix:
     - TRAVIS_GOARCH=amd64 TESTMODE=unit
     - TRAVIS_GOARCH=amd64 TESTMODE=integration
     - TRAVIS_GOARCH=386 TESTMODE=unit

appveyor.yml

@@ -5,6 +5,7 @@ os: Windows Server 2012 R2
 environment:
   GOPATH: c:\gopath
   CGO_ENABLED: 0
+  TIMESCALE_FACTOR: 20
   matrix:
     - GOARCH: 386
     - GOARCH: amd64

stream_test.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"io"
 	"runtime"
+	"strconv"
 	"time"
 
 	"os"
@@ -34,9 +35,10 @@ var _ = Describe("Stream", func() {
 	// on the CIs, the timing is a lot less precise, so scale every duration by this factor
 	scaleDuration := func(t time.Duration) time.Duration {
 		scaleFactor := 1
-		if os.Getenv("CI") == "true" {
+		if f, err := strconv.Atoi(os.Getenv("TIMESCALE_FACTOR")); err == nil { // parsing "" errors, so this works fine if the env is not set
-			scaleFactor = 20
+			scaleFactor = f
 		}
+		Expect(scaleFactor).ToNot(BeZero())
 		return time.Duration(scaleFactor) * t
 	}