ensure that series created only if data array not empty #179
Update GraphViewSeries.java

implement checking on the proper array before creating series
Merge pull request #180 from amuhebwa/series_initally_empty

ensure that series created only if data array not empty #179
use build tool version 20
refs #190 no arrayindexoutofbounds
refs #173 show vertical and/or horizontal grid lines or no grid lines
refs #83 warning if static labels and setNum...Labels are used together
refs #130 no more Log.d
refs #191 multiline labels (line break support)
refs #153 maven push properties
compatible to aapi version 7
graphview 3.1.3
Merge remote-tracking branch 'upstream/master'

Signed-off-by: Gabriel Herrera <jogah.cr@gmail.com>

Conflicts:
	GraphView.iml
	build.gradle