Started the "config" package.

The "cqlmm/config" package holds the struct and a function to load the
JSON configuration for a migrations project.
Started package "cmd".

Just laying out the "cqlmm" command.
Quick typo fix.
Implement the "init" command.

Ignore the "db" directory in .gitignore
cmd/cqlmm: Implement the "init" command.
Merge pull request #2 from nesv/initial-commands

Initial commands