Move WatchedContract to repositories

pkg/core/contract.go

@@ -0,0 +1,25 @@
+package core
+
+type Contract struct {
+	Attributes ContractAttributes
+	Hash       string
+}
+
+type ContractAttribute struct {
+	Name string
+	Type string
+}
+
+type ContractAttributes []ContractAttribute
+
+func (attributes ContractAttributes) Len() int {
+	return len(attributes)
+}
+
+func (attributes ContractAttributes) Swap(i, j int) {
+	attributes[i], attributes[j] = attributes[j], attributes[i]
+}
+
+func (attributes ContractAttributes) Less(i, j int) bool {
+	return attributes[i].Name < attributes[j].Name
+}