Add Makefile

[MistaTwista]

Makefile help newcomers to understand what to do with project.

By running:

$ make help

or just

$ make

there will be help message with all available commands.

Help message parsed from Makefile itself, by finding ## comments after command name.

Currently usefull commands are:

• dep - install dependencies and make vendoring folder
• test- run unit tests, but before it runs dep
• build - run test and build a binary into ./bin folder
• run - just execute binary
• rerun - build and run
• printvars - print all variables available for make its usefull when you need to debug some settings

On top of Makefile there are variables for all these commands, like:

• PROJECT_NAME
• BUILD_DIR
• VERSION
• BUILD_DATE
• COMMIT_SHA
• and LDFLAGS

LDFLAGS used on binary compilation, to inject some build data and get this information inside app.

Also this commit contains small changes in forming of version string

There is a good practices to add version with git tags, but also a commit message and build date.

[MistaTwista]

Added make clean command