strip the path of the mockgen executable when recording invocation (#82)

This commit changes the generated invocation comment to only print the name of the executable, rather than the full path.

mockgen/mockgen.go

@@ -295,7 +295,8 @@ func (g *generator) Generate(pkg *model.Package, outputPkgName string, outputPac
 	}
 	g.p("//")
 	g.p("// Generated by this command:")
-	g.p("//    %v", strings.Join(os.Args, " "))
+	// only log the name of the executable, not the full path
+	g.p("//    %v", strings.Join(append([]string{filepath.Base(os.Args[0])}, os.Args[1:]...), " "))
 
 	// Get all required imports, and generate unique names for them all.
 	im := pkg.Imports()