Ignore TAGS, etc.
Refactor indicators to use more parameters

Indicators now have access to a wider range of
parameters that they will need and will help
prevent recalculating common parameters multiple
times. It is also now possible to use parameters
that rely on fetching information from the
database.
Refactor tests/indicators to use new parameters
Break out static params into their own trait

Also fix some syntax errors
Merge pull request #258 from WorldBank-Transport/feature/refactor-params

Feature/refactor params