Fix typo (#1132)

* Fix typo

* Fix another typo

conn.go

@@ -461,7 +461,7 @@ func (c *Conn) recv() error {
 	}
 
 	if head.stream > c.streams.NumStreams {
-		return fmt.Errorf("gocql: frame header stream is beyond call exepected bounds: %d", head.stream)
+		return fmt.Errorf("gocql: frame header stream is beyond call expected bounds: %d", head.stream)
 	} else if head.stream == -1 {
 		// TODO: handle cassandra event frames, we shouldnt get any currently
 		framer := newFramer(c, c, c.compressor, c.version)
@@ -521,7 +521,7 @@ func (c *Conn) releaseStream(stream int) {
 	c.mu.Lock()
 	call := c.calls[stream]
 	if call != nil && stream != call.streamID {
-		panic(fmt.Sprintf("attempt to release streamID with ivalid stream: %d -> %+v\n", stream, call))
+		panic(fmt.Sprintf("attempt to release streamID with invalid stream: %d -> %+v\n", stream, call))
 	} else if call == nil {
 		panic(fmt.Sprintf("releasing a stream not in use: %d", stream))
 	}