Add FormFields spec

Issue #6.
Initial spec for text field.
Add spec for numeric field

Issue #6.
Test numeric fields being converted into fusion table column schema.
Add spec for Label field

Issue #6.
Labels don't result in a column in the fusion table schema.
Add spec for choice field

Issue #6.
Add spec for classification set field

Issue #6.
Fix numeric field column schema
Add spec for photo field

Issue #6.
Add spec for datetime field

Issue #6.
Add spec for address field

Issue #6.
Remove enumerable field
Add spec for signature field

Issue #6.
Move data nearer to specs
Move FusionColumnsSchema init code into #schema

Because it's good practice, homie. - Ghandi
Implement Section column schema

Issue #6.
Add spec to check that sections properly make columns for each nested
field.