Andrei Nesterov

Ok, will do it.

The changes from the [PR](https://github.com/AtherEnergy/rumqtt/pull/144) + I've updated the usage of MqttOptions in the tests. I've also added Travis CI support here.

I've kept Rustfmt and Clippy jobs for Travis in case you will want to start using them in the future. At the moment some code formatting is required before we...

@tekjar it seems as Travis CI integration is disabled for the project.

@tekjar I think we should decide first which approach we want to use for **MqttOptions** in **rumqtt**, because the implementation we have now isn't a **Builder pattern**. There are two...

I can change implementation to that implements Builder pattern if you prefer it. But we will have to remove getters to follow best practicies.

I suggest to fix one problem at a time. Currently, there is a bug in MqttOptions. I mean it shouldn't be the code like this: ```rust let opts = if...

> Maybe use crates like [this](https://docs.rs/derive_builder/0.7.1/derive_builder/) to avoid boilerplate? We have just a few attributes here. I would personally prefer explicit implementation making the code more readable. Implementing a builder...

> I don't understand why you consider this a bug. I consider this as a bug because we can't write the code: ```rust if let Some(value) = config.clean_session { opts.set_clean_session(value)...

> This is already a breaking change. I would rather design this for the next major release instead of accepting this PR now only to change it again Can I...