Propagate error response body to RTE (Issue scalaj#134)

Propagate response body to RuntimException to make sure the entire
reponse is logged. Logging usually revolves around getMessage whereas
the current code only overrides toString via Scala case class.

src/main/scala/scalaj/http/Http.scala

@@ -113,7 +113,7 @@ case class HttpStatusException(
   code: Int,
   statusLine: String,
   body: String
-) extends RuntimeException(code + " Error: " + statusLine)
+) extends RuntimeException(code + " Error: " + statusLine + " Details: " + body)
 
 /** Result of executing a [[scalaj.http.HttpRequest]]
   * @tparam T the body response since it can be parsed directly to things other than String

src/test/scala/scalaj/http/HttpTest.scala

@@ -3,9 +3,9 @@ package scalaj.http
 import java.io.{ByteArrayInputStream, ByteArrayOutputStream, IOException}
 import java.net.{HttpCookie, InetSocketAddress, Proxy}
 import java.util.zip.GZIPOutputStream
+
 import javax.servlet.{ServletRequest, ServletResponse}
 import javax.servlet.http.{HttpServlet, HttpServletRequest, HttpServletResponse}
-
 import org.eclipse.jetty.security.{ConstraintMapping, ConstraintSecurityHandler, HashLoginService}
 import org.eclipse.jetty.security.authentication.{BasicAuthenticator, DigestAuthenticator, LoginAuthenticator}
 import org.eclipse.jetty.server.{Request, Server}
@@ -15,9 +15,10 @@ import org.eclipse.jetty.servlets.ProxyServlet
 import org.eclipse.jetty.util.security.{Constraint, Credential}
 import org.junit.Assert._
 import org.junit.Test
-
 import scalaj.http.HttpConstants._
 
+import scala.util.Try
+
 
 class HttpTest {
 
@@ -470,6 +471,14 @@ class HttpTest {
     HttpResponse("hi", 400, Map.empty).throwError
   }
 
+  @Test
+  def throwServerErrorThrowsWithStatusAndBody: Unit = {
+    val httpResp = HttpResponse("stacktrace", 400, Map("Status" -> IndexedSeq("HTTP/1.1 400 Bad Request")))
+    val statusException = Try(httpResp.throwError).failed.get
+    assertEquals(s"${httpResp.code} Error: ${httpResp.headers("Status")(0)} Details: ${httpResp.body}",
+      statusException.getMessage)
+  }
+
   @Test
   def throwErrorOkWith200: Unit = {
     assertEquals(200, HttpResponse("hi", 200, Map.empty).throwError.code)