Thallium exercises

This section contains three exercises meant to accompany Mochi tutorials. These tutorials focus on using the C++ language, with the Thallium library. They revolve around the development of a phonebook microservice, i.e. a service that associates names (std::string`s) with phone numbers (which will be represented as :code:`uint64_t values).

The three exercises are relatively independent of each other, though we recommend completing each of them to get a good understanding of Thallium and Mochi in general.