test: install crud from master

Currently `make deps`, which is used for tests, installs specified
version of `crud`. Such approach complicates integration with Tarantool:
when a patch in Tarantool breaks integration with both `crud` and
`go-tarantool` (because it uses `crud`), one needs to fix `crud`, then
release it and then bump it to the new version in makefile of
`go-tarantool`. Let's simplify this process - simply install `crud` from
its master for tests. Note that such approach has a drawback - any commit
in `crud` can break integration with `go-tarantool`.

Makefile

@@ -24,7 +24,7 @@ clean:
 deps: clean
 	@(command -v tt > /dev/null || (echo "error: tt not found" && exit 1))
 	( cd ./queue/testdata; tt rocks install queue 1.3.0 )
-	( cd ./crud/testdata; tt rocks install crud 1.4.1 )
+	( cd ./crud/testdata; tt rocks install crud )
 
 .PHONY: datetime-timezones
 datetime-timezones: