rework run script to remove python3 logic
diff --git a/run b/run
index 9bea31f..7f18fa9 100755
--- a/run
+++ b/run
@@ -10,9 +10,8 @@
 from tools import cov
 
 
-is_python3 = bool(sys.version_info.major == 3)
-has_python34 = False
 verbose = False
+
 repo_dir = os.path.abspath(os.path.dirname(__file__))
 path_to_cov = os.path.join(repo_dir, 'tools', 'cov.py')
 path_to_runner = os.path.join(repo_dir, 'typ', 'runner.py')
@@ -28,8 +27,6 @@
 
 def main(argv):
     parser = argparse.ArgumentParser(prog='run')
-    parser.add_argument('--no3', action='store_true',
-                        help='Do not run the tests under Python 3.')
     parser.add_argument('-v', '--verbose', action='store_true')
     subps = parser.add_subparsers()
 
@@ -60,13 +57,6 @@
     global verbose
     if args.verbose:
         verbose = True
-    global has_python34
-    if not args.no3:
-        try:
-            ver = subprocess.check_output(['python3', '--version'])
-            has_python34 = ver.split()[1] >= '3.4'
-        except:
-            pass
     args.func(args)
 
 
@@ -81,11 +71,8 @@
         args.source = [os.path.join(repo_dir, 'typ')]
     argv = cov.argv_from_args(args)
     cov_args = [path_to_runner, '-j', '1']
-    print('Running coverage of unit tests for Python 2.7.')
-    call(['python', path_to_cov] + argv + cov_args)
-    if has_python34:
-        print('Running coverage of unit tests for Python 3.4.')
-        call(['python3', path_to_cov] + argv + cov_args)
+    python = sys.executable
+    call([python, path_to_cov] + argv + cov_args)
 
 
 def run_help(args):
@@ -99,20 +86,17 @@
 
 
 def run_tests(args):
+    python = sys.executable
     print('Testing running the typ module directly if it is in sys.path.')
-    call(['python', '-m', 'typ', 'typ.tests.main_test.TestMain.test_basic'])
+    call([python, '-m', 'typ', 'typ.tests.main_test.TestMain.test_basic'])
 
     print('Testing running the runner directly if nothing is in sys.path.')
     home_dir = os.environ['HOME']
-    call(['python', path_to_runner, 'typ.tests.main_test.TestMain.test_basic'],
+    call([python, path_to_runner, 'typ.tests.main_test.TestMain.test_basic'],
          cwd=home_dir)
 
-    # Now run all the tests under Python2 and Python3.
-    print('Running the unit tests under Python 2.')
-    call(['python', path_to_runner])
-    if has_python34:
-        print('Running the unit tests under Python 3.4.')
-        call(['python3', path_to_runner])
+    print('Running the unit tests.')
+    call([python, path_to_runner])
 
 
 if __name__ == '__main__':