[bazel] Add fixes for --incompatible_load_cc_rules_from_bzl (#351)

* [bazel] Add fixes for --incompatible_load_cc_rules_from_bzl

Starting with Bazel 1.0 (September 2019), C++ rules will need to be
loaded from the @rules_cc repository. This change adds the required
loads for that. For full compatibility, we will need versions of
googletest and google-benchmark that also includes these loads.

* Run buildifier again after merge
diff --git a/absl/algorithm/BUILD.bazel b/absl/algorithm/BUILD.bazel
index c506f3b..2ee8c09 100644
--- a/absl/algorithm/BUILD.bazel
+++ b/absl/algorithm/BUILD.bazel
@@ -14,6 +14,7 @@
 # limitations under the License.
 #
 
+load("@rules_cc//cc:defs.bzl", "cc_library", "cc_test")
 load(
     "//absl:copts/configure_copts.bzl",
     "ABSL_DEFAULT_COPTS",