Introduce jsdoc examples to insight.DataSet

Examples show the data along with the differentiation between
one-to-one and many-to-one groupings.
Improve insight.DataSet.group example

In response to PR feedback. Change should hopefully provide additional
clarification as to how group is used.
Updated DataSet.group @example
Merge pull request #1 from niksoper/feature/dataset-group-doc-example

Updated DataSet.group @example
Merge pull request #254 from matthewdunsdon/feature/dataset-group-doc-example

Introduce jsdoc examples to insight.DataSet.group
Fix missing package dependency

- Missing ```grunt-zip```
- Packages reordered by ```npm```.
Merge pull request #257 from matthewdunsdon/fix-package-json

Fix missing package dependency
Created an alternative to the LightTheme, RedTheme
Merge branch 'develop' of https://github.com/ScottLogic/insight into feature/introduce-new-theme
Merge branch 'develop' of https://github.com/ScottLogic/insight into develop
Indentation change after upgrading to grunt-jsbeautifier 0.2.7
Using 'mean' rather than 'Average' for means on Groupings
Removed Grouping.isOrdered()

The private postAggregationCalculations function in Grouping was passing
self.orderingFunction to self.extractData, but only if
Grouping.isOrdered returned true. However, the base
DataProvider.extractData function would still order the data using the
self.orderingFunction, rendering Grouping.isOrdered useless.
Removed Grouping.isOrdered() from tests.
Using lowercase for Grouping sum, count and total calculated properties
Updated documentation for Dimension and Grouping
Reduced the size of the one-to-many Grouping.extractData example
Updated change log
More documentation for Grouping: sum, cumulative, count and mean.
Updated change log