[SPARK-9633] [BUILD] SBT download locations outdated; need an update

Remove 2 defunct SBT download URLs and replace with the 1 known download URL. Also, use https.
Follow up on https://github.com/apache/spark/pull/7792

Author: Sean Owen <sowen@cloudera.com>

Closes #7956 from srowen/SPARK-9633 and squashes the following commits:

caa40bd [Sean Owen] Remove 2 defunct SBT download URLs and replace with the 1 known download URL. Also, use https.

Conflicts:
	sbt/sbt-launch-lib.bash
diff --git a/sbt/sbt-launch-lib.bash b/sbt/sbt-launch-lib.bash
index 64e40a8..2fbb060 100755
--- a/sbt/sbt-launch-lib.bash
+++ b/sbt/sbt-launch-lib.bash
@@ -37,8 +37,7 @@
 
 acquire_sbt_jar () {
   SBT_VERSION=`awk -F "=" '/sbt\\.version/ {print $2}' ./project/build.properties`
-  URL1=http://typesafe.artifactoryonline.com/typesafe/ivy-releases/org.scala-sbt/sbt-launch/${SBT_VERSION}/sbt-launch.jar
-  URL2=http://repo.typesafe.com/typesafe/ivy-releases/org.scala-sbt/sbt-launch/${SBT_VERSION}/sbt-launch.jar
+  URL1=https://dl.bintray.com/typesafe/ivy-releases/org.scala-sbt/sbt-launch/${SBT_VERSION}/sbt-launch.jar
   JAR=sbt/sbt-launch-${SBT_VERSION}.jar
 
   sbt_jar=$JAR
@@ -50,9 +49,9 @@
     printf "Attempting to fetch sbt\n"
     JAR_DL=${JAR}.part
     if hash curl 2>/dev/null; then
-      (curl --progress-bar ${URL1} > ${JAR_DL} || curl --progress-bar ${URL2} > ${JAR_DL}) && mv ${JAR_DL} ${JAR}
+      curl --progress-bar --fail --location ${URL1} > "${JAR_DL}" && mv "${JAR_DL}" "${JAR}"
     elif hash wget 2>/dev/null; then
-      (wget --progress=bar ${URL1} -O ${JAR_DL} || wget --progress=bar ${URL2} -O ${JAR_DL}) && mv ${JAR_DL} ${JAR}
+      wget --progress=bar ${URL1} -O "${JAR_DL}" && mv "${JAR_DL}" "${JAR}"
     else
       printf "You do not have curl or wget installed, please install sbt manually from http://www.scala-sbt.org/\n"
       exit -1