minor hotfix for OptionTest.test_help_6, OptionTest.test_version_2 and tests/Readme.md FAQ (#494)

Co-authored-by: Ivan Lazarev <i.lazarev@postgrespro.ru>

Author: avaness

tests/Readme.md

@@ -1,4 +1,4 @@
-[see wiki](https://confluence.postgrespro.ru/display/DEV/pg_probackup)
+****[see wiki](https://confluence.postgrespro.ru/display/DEV/pg_probackup)
 
 ```
 Note: For now these tests work on Linux and "kinda" work on Windows
@@ -50,3 +50,32 @@ Usage:
  export PG_CONFIG=/path/to/pg_config
  python -m unittest [-v] tests[.specific_module][.class.test]
 ```
+
+### Troubleshooting FAQ
+
+#### python test failures
+1. Test failure reason like 
+```
+testgres.exceptions.QueryException ERROR:  could not open extension control file "/home/avaness/postgres/postgres.build/share/extension/amcheck.control": No such file or directory
+```
+
+*Solution*: you have no `<postgres_src_root>/contrib/` extensions installed
+
+```commandline
+cd <postgres_src_root>
+make world install
+```
+
+2. Test failure
+
+```
+FAIL: test_help_6 (tests.option.OptionTest)
+```
+
+*Solution*: you didn't configure postgres build with `--enable-nls` 
+
+```commandline
+cd <postgres_src_root>
+make distclean
+<your-./configure-cmdline> --enable-nls
+```

tests/expected/option_help_ru.out

@@ -178,6 +178,7 @@ pg_probackup - утилита для управления резервным к
                  [--remote-proto] [--remote-host]
                  [--remote-port] [--remote-path] [--remote-user]
                  [--ssh-options]
+                 [--dry-run]
                  [--help]
 
 Подробнее читайте на сайте <https://github.com/postgrespro/pg_probackup>.

tests/option.py

@@ -24,7 +24,7 @@ def test_version_2(self):
         """help options"""
         with open(os.path.join(self.dir_path, "expected/option_version.out"), "rb") as version_out:
             self.assertIn(
-                version_out.read().decode("utf-8"),
+                version_out.read().decode("utf-8").strip(),
                 self.run_pb(["--version"])
             )