Delete //tools:par_test (#133)

The test is brittle and shouldn't be used as a security guarantee anyway. See https://github.com/bazelbuild/rules_python/issues/117#issuecomment-438704277 for more context.

Fixes #117.

tools/BUILD

diff --git a/tools/BUILD b/tools/BUILD
index 29ffe59..780484e 100644
--- a/tools/BUILD
+++ b/tools/BUILD
@@ -15,16 +15,5 @@
 
 licenses(["notice"])  # Apache 2.0
 
-# This is generated and updated by ./update_tools.sh
+# These files are generated and updated by ./update_tools.sh
 exports_files(["piptool.par", "whltool.par"])
-
-py_test(
-    name = "par_test",
-    srcs = ["par_test.py"],
-    data = [
-        "//rules_python:piptool.par",
-        "//rules_python:whltool.par",
-        ":piptool.par",
-        ":whltool.par",
-    ],
-)

tools/par_test.py

diff --git a/tools/par_test.py b/tools/par_test.py
deleted file mode 100644
index 0b6d1d8..0000000
--- a/tools/par_test.py
+++ /dev/null
@@ -1,93 +0,0 @@
-# Copyright 2017 The Bazel Authors. All rights reserved.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#    http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-import difflib
-import hashlib
-import os
-import unittest
-import zipfile
-
-
-def TestData(name):
-  return os.path.join(os.environ['TEST_SRCDIR'], 'io_bazel_rules_python', name)
-
-
-def _format_toc(filename):
-    """Return a table of contents for the zip file as a string.
-
-    Args:
-        filename (str): Path to zip file
-
-    Returns: directory listed in format matching zipfile.printdir()
-    """
-    zf = zipfile.ZipFile(filename)
-    lines = []
-    lines.append("%-46s %19s %12s" % ("File Name", "Modified    ", "Size"))
-    for zinfo in zf.filelist:
-        date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
-        lines.append("%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size))
-    return lines
-
-
-class WheelTest(unittest.TestCase):
-
-    def _diff_zip(self, filename1, filename2):
-        """Compare two zip files for equality, pretty-printing differences."""
-        with open(filename1, 'rb') as file1:
-            contents1 = file1.read()
-        with open (filename2, 'rb') as file2:
-            contents2 = file2.read()
-        if contents1 != contents2:
-            toc1 = _format_toc(filename1)
-            toc2 = _format_toc(filename2)
-            sha1 = hashlib.sha256(filename1).hexdigest()
-            sha2 = hashlib.sha256(filename2).hexdigest()
-            diff = difflib.unified_diff(toc1, toc2)
-            diff_str = '\n'.join(diff) or (
-                'No differences in zip contents, only in zip headers [not shown]')
-            message = r'''Files do not match.
-
-************************************************************************
-File 1: %s
-Length in bytes: %s
-SHA256: %s
-************************************************************************
-File 2: %s
-Length in Bytes: %s
-SHA256: %s
-************************************************************************
-Zip Content Diff:
-%s
-************************************************************************
-''' % (
-    filename1,
-    len(contents1),
-    sha1,
-    filename2,
-    len(contents2),
-    sha2,
-    diff_str,
-)
-            self.assertEquals(contents1, contents2, message)
-
-    def test_piptool_matches(self):
-        self._diff_zip(TestData('rules_python/piptool.par'),
-                       TestData('tools/piptool.par'))
-
-    def test_whltool_matches(self):
-        self._diff_zip(TestData('rules_python/whltool.par'),
-                       TestData('tools/whltool.par'))
-
-if __name__ == '__main__':
-  unittest.main()