[fix] Add the dir "logs" into the tarball stracture (#111)

With the changes introduced under #109
We missed the `logs` directory from the tarbal generation.

We fix this now.

before:
```
├── LICENSE.txt
├── NOTICE.txt
├── README.md
├── bin
│   └── mattermost-push-proxy
└── config
    ├── build.txt
    └── mattermost-push-proxy.sample.json
```

after:
```
├── LICENSE.txt
├── NOTICE.txt
├── README.md
├── bin
│   └── mattermost-push-proxy
├── config
│   ├── build.txt
│   └── mattermost-push-proxy.sample.json
└── logs
```

Makefile

@@ -157,6 +157,7 @@ package-software:  ## to package the binary
 		cp -RL config $(GO_OUT_BIN_DIR)/$${target}_temp/config; \
 		echo $(APP_VERSION) > $(GO_OUT_BIN_DIR)/$${target}_temp/config/build.txt; \
 		cp LICENSE.txt NOTICE.txt README.md $(GO_OUT_BIN_DIR)/$${target}_temp; \
+		mkdir $(GO_OUT_BIN_DIR)/$${target}_temp/logs; \
 		mv $$file $(GO_OUT_BIN_DIR)/$${target}_temp/bin/mattermost-push-proxy; \
 		mv $(GO_OUT_BIN_DIR)/$${target}_temp $(GO_OUT_BIN_DIR)/$${target}; \
 		tar -czf $(GO_OUT_BIN_DIR)/$${target}.tar.gz -C $(GO_OUT_BIN_DIR) $${target}; \