Added warning about max comment length

Author: snorklerjoe

README.md

@@ -106,7 +106,7 @@ void setup() {
   //code = server.postTemperature(32);
   //code = server.postLightIntensity(12.5);
   //code = server.postPressure(25.2);
-  //code = server.postComment("Hello World!");
+  //code = server.postComment("Hello World!");  // Comments may only be 32 chars long!
   if(code == 201)
     Serial.println("Data posted successfully!");
   else

server.cpp

@@ -143,7 +143,7 @@ int CubeServer::postLightIntensity(double value) {
   return this->post(data);
 }
 
-int CubeServer::postComment(String value) {
+int CubeServer::postComment(String value) {  // 32 chars max!
   char data[64];
   sprintf(data, "{\"type\": \"comment\", \"value\": \"%s\"}", value);
   return this->post(data);