Don't use force download mode in plugin tests on Windows

It tries to replace JARs that are in use, and fails as these are locked
on Windows

plugin/src/sbt-test/sbt-coursier/credentials-from-file/build.sbt

@@ -4,6 +4,11 @@ resolvers += "authenticated" at "http://localhost:8080"
 
 coursierCredentials += "authenticated" -> coursier.Credentials(file("credentials"))
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}
 
 libraryDependencies += "com.abc" % "test" % "0.1"

plugin/src/sbt-test/sbt-coursier/credentials/build.sbt

@@ -4,6 +4,11 @@ resolvers += "authenticated" at "http://localhost:8080"
 
 coursierCredentials += "authenticated" -> coursier.Credentials("user", "pass")
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}
 
-libraryDependencies += "com.abc" % "test" % "0.1"
+libraryDependencies += "com.abc" % "test" % "0.1"

plugin/src/sbt-test/sbt-coursier/exclude-dependencies/build.sbt

@@ -1,6 +1,11 @@
 scalaVersion := "2.11.8"
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}
 
 libraryDependencies += "com.github.alexarchambault" %% "argonaut-shapeless_6.1" % "1.0.0-RC1"
 

plugin/src/sbt-test/sbt-coursier/from/build.sbt

@@ -1,6 +1,11 @@
 scalaVersion := "2.11.8"
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}
 
 libraryDependencies += "com.chuusai" %% "shapeless" % "2.3.41" from {
   

plugin/src/sbt-test/sbt-coursier/maven-compatible/build.sbt

@@ -1,6 +1,11 @@
 scalaVersion := "2.11.8"
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}
 
 resolvers += Resolver.url(
   "webjars-bintray",

plugin/src/sbt-test/sbt-coursier/simple/build.sbt

@@ -1,3 +1,8 @@
 scalaVersion := "2.11.8"
 
-coursierCachePolicies := Seq(coursier.CachePolicy.ForceDownload)
+coursierCachePolicies := {
+  if (sys.props("os.name").startsWith("Windows"))
+    coursierCachePolicies.value
+  else
+    Seq(coursier.CachePolicy.ForceDownload)
+}