Request Compose compat to include 0.8 please (#103)

Gadfly.jl now uses the much improved Compose.jl v0.8 and cross dependencies are a little tricky.

Author: dehann

Project.toml

@@ -18,7 +18,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 ArnoldiMethod = "0.0.4"
 ColorTypes = "0.9"
 Colors = "0.11"
-Compose = "0.7"
+Compose = "0.7, 0.8"
 LightGraphs = "1.1"
 VisualRegressionTests = ">= 0.2"
 julia = "1"