Remove luatest and checks submodules

The `test-run` project is rarely updated these days while `luatest` is
rapidly developing. Let's remove the `luatest` submodule from `test-run`
to ease luatest bumps in projects using `test-run`. Now, `luatest` is
supposed to be added as a submodule to all projects using `test-run`.

By default, `test-run` looks for `luatest` in `../third_party/luatest`,
but this can be overridden with the new `--luatestdir option`.

Note that we also remove the `checks` submodule, which was added as
a dependency of `luatest`. It was built in Tarantool in 2.11.0 so
there's no need in it anymore.

Closes #453

Author: locker

.gitmodules

@@ -4,9 +4,3 @@
 [submodule "lib/tarantool-python"]
 	path = lib/tarantool-python
 	url = https://github.com/tarantool/tarantool-python.git
-[submodule "lib/checks"]
-	path = lib/checks
-	url = https://github.com/tarantool/checks.git
-[submodule "lib/luatest"]
-	path = lib/luatest
-	url = https://github.com/tarantool/luatest.git

.luacheckrc

@@ -27,6 +27,4 @@ include_files = {
 exclude_files = {
     "lib/tarantool-python",
     "test/test-tarantool/*.test.lua",
-    "lib/luatest/**",
-    "lib/checks/**",
 }

lib/__init__.py

@@ -63,25 +63,25 @@ def module_init():
         pass
 
     args.builddir = os.path.abspath(os.path.expanduser(args.builddir))
+    args.luatestdir = os.path.abspath(os.path.expanduser(args.luatestdir))
 
     SOURCEDIR = os.path.dirname(os.getcwd())
     BUILDDIR = args.builddir
+    LUATESTDIR = args.luatestdir
     os.environ["SOURCEDIR"] = SOURCEDIR
     os.environ["BUILDDIR"] = BUILDDIR
     soext = sys.platform == 'darwin' and 'dylib' or 'so'
 
     os.environ['LUA_PATH'] = (
             SOURCEDIR + '/?.lua;' + SOURCEDIR + '/?/init.lua;'
-            + os.environ['TEST_RUN_DIR'] + '/lib/checks/?.lua;'
-            + os.environ['TEST_RUN_DIR'] + '/lib/luatest/?/init.lua;'
-            + os.environ['TEST_RUN_DIR'] + '/lib/luatest/?.lua;;'
+            + LUATESTDIR + '/?/init.lua;' + LUATESTDIR + '/?.lua;;'
     )
 
     os.environ["LUA_CPATH"] = BUILDDIR+"/?."+soext+";;"
     os.environ["REPLICATION_SYNC_TIMEOUT"] = str(args.replication_sync_timeout)
     os.environ['MEMTX_ALLOCATOR'] = args.memtx_allocator
 
-    prepend_path(os.path.join(os.environ['TEST_RUN_DIR'], 'lib/luatest/bin'))
+    prepend_path(os.path.join(LUATESTDIR, 'bin'))
 
     TarantoolServer.find_exe(args.builddir, executable=args.executable)
     UnittestServer.find_exe(args.builddir)

lib/checks

@@ -125,7 +125,7 @@ def find_exe(cls, builddir):
         cls.binary = TarantoolServer.binary
         cls.debug = bool(re.findall(r'^Target:.*-Debug$', str(cls.version()),
                                     re.M))
-        cls.luatest = os.environ['TEST_RUN_DIR'] + '/lib/luatest/bin/luatest'
+        cls.luatest = os.path.join(Options().args.luatestdir, 'bin/luatest')
 
     @classmethod
     def verify_luatest_exe(cls):

lib/luatest

@@ -228,6 +228,21 @@ def __init__(self):
                     Default: false.
                     """))
 
+        parser.add_argument(
+                "--luatestdir",
+                dest="luatestdir",
+                default="../third_party/luatest",
+                help=format_help(
+                    """
+                    Path to luatest directory.
+
+                    Beware: A relative path is resolved against the directory,
+                    where all tests reside. **NOT** a current directory of a
+                    parent shell.
+
+                    Default: ../third_party/luatest
+                    """))
+
         parser.add_argument(
                 "--builddir",
                 dest="builddir",