Redefeind interfaces; Added better modelled data strauctures

Router interface has been redefined which fits better with what we are
looking for.

Routing table now offers a comprehensive set of information about its
entries which will make up for rich queries in the future

Query interface has been defined to enable current basic and more
advanced queries in the future.

router/table.go

@@ -0,0 +1,58 @@
+package router
+
+import "errors"
+
+var (
+	// ErrRouteNotFound is returned when no rout was found
+	ErrRouteNotFound = errors.New("route not found")
+)
+
+// Entry is micro network routing table entry
+type Entry struct {
+	// NetID is micro network ID
+	NetID string
+	// Hop is the next route hop
+	Hop Router
+	// Metric is route cost metric
+	Metric int
+}
+
+// Table is routing table
+// It maps service name to routes
+type Table struct {
+	// m stores routing table map
+	m map[string][]Entry
+}
+
+// NewTable creates new routing table and returns it
+func NewTable() *Table {
+	return &Table{
+		m: make(map[string][]Entry),
+	}
+}
+
+// TODO: Define lookup query interface
+// Lookup looks up entry in the routing table
+func (t *Table) Lookup() (*Entry, error) {
+	return nil, nil
+}
+
+// Remove removes entry from the routing table
+func (t *Table) Remove(e *Entry) error {
+	return nil
+}
+
+// Update updates routin entry
+func (t *Table) Update(e *Entry) error {
+	return nil
+}
+
+// Size returns the size of the routing table
+func (t *Table) Size() int {
+	return 0
+}
+
+// String returns text representation of routing table
+func (t *Table) String() string {
+	return ""
+}