Fix our Java 7 build

  - Follow redirects when downloading files:
       The github provided file lies after several redirect, giving a bad jars
       (see http://ci.bazel.io/job/Bazel/JAVA_VERSION=1.7,PLATFORM_NAME=linux-x86_64/144/console).
  - Remove building tools as part of the determinism tests: 
        With recent update, JavaBuilder can no longer be built with Java 7, 
        so we use a pre-built binary from version 0.1.0. However, the
        determinism test was still using it as a point of comparison. Removing
        tools from the determinism test prevent building JavaBuilder without
        giving up on testing actual determinism (building Bazel already contains
        all the edge-cases).

Tested with `bash -c 'export JAVA_VERSION=1.7; source scripts/ci/build.sh; bazel_build'`

--
MOS_MIGRATED_REVID=104480161
diff --git a/src/BUILD b/src/BUILD
index a07be09..8076a73 100644
--- a/src/BUILD
+++ b/src/BUILD
@@ -35,8 +35,8 @@
 )
 
 # Try to grab the java version from the java_toolchain.
-# Unfortunately, we don't the javac options so we cannot get it from
-# the command-line options.
+# Unfortunately, we don't have access to the javac options
+# so we cannot get it from the command-line options.
 genquery(
     name = "java_toolchain_content",
     expression = "kind(java_toolchain, deps(//tools/defaults:java_toolchain))",
@@ -137,16 +137,6 @@
     ],
 )
 
-filegroup(
-    name = "tools",
-    srcs = [
-        "//src/java_tools/buildjar:JavaBuilder_deploy.jar",
-        "//src/java_tools/buildjar/java/com/google/devtools/build/buildjar/genclass:GenClass_deploy.jar",
-        "//src/java_tools/singlejar:SingleJar_deploy.jar",
-        "//third_party/ijar",
-    ],
-)
-
 config_setting(
     name = "darwin",
     values = {"cpu": "darwin"},