Explicitly check for a minimum bazel version of 0.17.1 (#218)

Author: gregmagolan

WORKSPACE

@@ -43,8 +43,10 @@ load("@angular//packages/bazel:package.bzl", "rules_angular_dependencies")
 
 rules_angular_dependencies()
 
-load("@build_bazel_rules_nodejs//:defs.bzl", "node_repositories", "yarn_install")
+load("@build_bazel_rules_nodejs//:defs.bzl", "check_bazel_version", "node_repositories", "yarn_install")
 
+# The minimum bazel version to use with this example repo is 0.17.1
+check_bazel_version("0.17.1")
 node_repositories(
     node_version = "10.9.0",
     yarn_version = "1.9.2",