CompatHelper: bump compat for MetaGraphs to 0.8, (keep existing compat)

Author: CompatHelper Julia

Project.toml

@@ -28,7 +28,7 @@ DataStructures = "0.18, 0.19"
 Distributions = "0.25"
 Graphs = "1"
 IterTools = "1.4"
-MetaGraphs = "0.7"
+MetaGraphs = "0.7, 0.8"
 OMEinsum = "0.7, 0.8"
 PrettyTables = "2.2, 3"
 SimpleTraits = "0.9"