Upgrade to a new Bazel version

This one has better performance and various new features. It also
prevents us from falling too far behind upstream.

Change-Id: I3b8e1c5bda886ea2e990523af9e6de2434c784be
diff --git a/tools/build_rules/fortran.bzl b/tools/build_rules/fortran.bzl
index f8d0add..2d6e4db 100644
--- a/tools/build_rules/fortran.bzl
+++ b/tools/build_rules/fortran.bzl
@@ -36,11 +36,11 @@
     progress_message = 'Building %s' % ctx.outputs.pic_o.short_path,
   )
 
-def _define_fortran_output(attrs):
-  if not attrs.src.name.endswith('.f'):
+def _define_fortran_output(src):
+  if not src.name.endswith('.f'):
     fail('Fortran files must end in \'.f\'', 'src')
 
-  fortran_file_base = attrs.src.name[:-2]
+  fortran_file_base = src.name[:-2]
   return {
     'pic_o': fortran_file_base + '.pic.o',
   }
diff --git a/tools/build_rules/protobuf.bzl b/tools/build_rules/protobuf.bzl
index fe6af4f..d5f4284 100644
--- a/tools/build_rules/protobuf.bzl
+++ b/tools/build_rules/protobuf.bzl
@@ -19,8 +19,8 @@
     ],
   )
 
-def _do_proto_cc_library_outputs(attr):
-  basename = attr.src.name[:-len('.proto')]
+def _do_proto_cc_library_outputs(src):
+  basename = src.name[:-len('.proto')]
   return {
     'pb_h': '%s.pb.h' % basename,
     'pb_cc': '%s.pb.cc' % basename,
@@ -37,7 +37,7 @@
     '_protoc': attr.label(
       default = Label('//third_party/protobuf:protoc'),
       executable = True,
-      cfg = HOST_CFG,
+      cfg = 'host',
     ),
     '_well_known_protos': attr.label(
       default = Label('//third_party/protobuf:well_known_protos'),
diff --git a/tools/build_rules/ruby.bzl b/tools/build_rules/ruby.bzl
index 7c02745..2c93596 100644
--- a/tools/build_rules/ruby.bzl
+++ b/tools/build_rules/ruby.bzl
@@ -51,7 +51,7 @@
   ),
   'data': attr.label_list(
     allow_files = True,
-    cfg = DATA_CFG,
+    cfg = 'data',
   ),
 }
 
@@ -84,6 +84,7 @@
   attrs = _ruby_attrs + {
     '_ruby_linker': attr.label(
       executable = True,
+      cfg = 'host',
       default = Label('//tools/ruby:standalone_ruby'),
     )
   },