Added Required ruby version to gem spec

Using lowest Travis tested version
Updated 2.1.x version to 2.1.4 in Travis config
Slight refactor (CodeClimate said it smells)
Added TableSettings class, mods to DeepMerge util

DeepMerge split into specific TemplateOptions and TableOptions
TableSettings defines settings that will be used in tables
Added prawn-table as a dependency
Added Table functionality

Table
- ReadMe outlines purpose and methods of the table

Builder
- added table_with method

ReadMe
- Updated with new info about Table and TableSettings

Tests for all above
Refactor smelly chunk for style setting
Added require for PDF::Insepector

Oversight from last commit, thanks Travis