message: Migrate message to felice from kafka-go

[tealeg]

This PR migrates the Message and Option types from kafka-go into a new sub-package of felice.

Additionally, it does the following;

• set up dep dependency definitions
• initiate a .gitignore file to avoid checking in the vendor directory
• radically expand test coverage from the state of kafka-go

[yaziine]

💪🏼

[jhchabran]

radical expand test coverage from the state of kafka-go

❤️

[asdine]

Great job 👍