Make it clearer what is the package and what is the simulation

Validity method was set to SimpleParams

Not great, but will do for now

Zero means was causing NAs in counts

Some parameters weren't being passed from SCESet method to matrix
method

* Add Anthony's comments
* Use biocLite to install

* 'master' of github.com:Oshlack/splatter:
  Add Travis CI

* 'master' of github.com:lazappi/splatter:
  Update README

* vignette:
  Run checks
  Add other sims section
  Add simulation section
  Add estimation section
  Add parameters sections
  Add splatter vignette

* scDD:
  Run checks
  Add scDD tests
  Add scDDSimulate function
  Add scDDEstimate
  Add SCDDParams object

Getting note about scDatEx, but think it should be fine...

* lun2:
  Run checks
  Document lun2Simulate and add tests
  Add lun2Simulate function
  Add lun2Estimate function
  Document Lun2Params
  Add Lun2Params object