Bazel: Remove version check

Recent Bazel releases perform Bazel version check, based on
.bazelversion file.

Change-Id: Ica9bc5932df63939abebf00db6d1f38a20693e9f

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 77baff8..aa5825f 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -9,22 +9,6 @@
     urls = ["https://github.com/bazelbuild/rules_python/archive/4b84ad270387a7c439ebdccfd530e2339601ef27.tar.gz"],
 )
 
-http_archive(
-    name = "bazel_skylib",
-    sha256 = "bbccf674aa441c266df9894182d80de104cabd19be98be002f6d478aaa31574d",
-    strip_prefix = "bazel-skylib-2169ae1c374aab4a09aa90e65efe1a3aad4e279b",
-    urls = ["https://github.com/bazelbuild/bazel-skylib/archive/2169ae1c374aab4a09aa90e65efe1a3aad4e279b.tar.gz"],
-)
-
-# Check Bazel version when invoked by Bazel directly
-load("//tools:bazelisk_version.bzl", "bazelisk_version")
-
-bazelisk_version(name = "bazelisk_version")
-
-load("@bazelisk_version//:check.bzl", "check_bazel_version")
-
-check_bazel_version()
-
 load("//tools:bazlets.bzl", "load_bazlets")
 
 load_bazlets(

tools/bazelisk_version.bzl

diff --git a/tools/bazelisk_version.bzl b/tools/bazelisk_version.bzl
deleted file mode 100644
index d8b3d10..0000000
--- a/tools/bazelisk_version.bzl
+++ /dev/null
@@ -1,16 +0,0 @@
-_template = """
-load("@bazel_skylib//lib:versions.bzl", "versions")
-
-def check_bazel_version():
-  versions.check(minimum_bazel_version = "{version}")
-""".strip()
-
-def _impl(repository_ctx):
-    repository_ctx.symlink(Label("@//:.bazelversion"), ".bazelversion")
-    bazelversion = repository_ctx.read(".bazelversion").strip()
-
-    repository_ctx.file("BUILD", executable = False)
-
-    repository_ctx.file("check.bzl", executable = False, content = _template.format(version = bazelversion))
-
-bazelisk_version = repository_rule(implementation = _impl)