Reorganized compile.sh

Now the blessed Bazel binary is self-hosted and correctly labeled.
All tools are also built using Bazel and labeled with the release.
At the end of the compilation, the output folder only host the
Bazel binary now. We use temporary folders to store the intermediate
artifacts.

Also integrated ./bootstrap_test.sh in compile.sh so there is only
one script for everything regarding bootstraping Bazel.

--
Change-Id: Idadbd075e7b8ecb6e306b919b7a73c647c5cfbae
Reviewed-on: https://bazel-review.googlesource.com/#/c/1460/
MOS_MIGRATED_REVID=95625880

.travis/build.sh

@@ -29,5 +29,5 @@ else
     sudo update-alternatives --set nc /bin/nc.traditional
     export JAVA_HOME=/usr/lib/jvm/java-8-oracle
     export JAVA_OPTS="-Xmx3000m"
-    ./bootstrap_test.sh all
+    ./compile.sh all
 fi

.travis/prepare-for-deploy.sh

@@ -26,7 +26,7 @@ function create_zip() {
   local bazel_dir
   bazel_dir=bazel-$git_hash
   mkdir $bazel_dir
-  cp bazel-bin/src/bazel $bazel_dir
+  cp output/bazel $bazel_dir
   sha256sum $bazel_dir/bazel > $bazel_dir/sha256.txt
   cat > $bazel_dir/README.md <<EOF
 Bazel binary built by Travis CI