Missing #include <avr/dtostrf.h> No such file or directory Arduino IDE 1.6.10

Hello,

I am currently trying to run this code

#include <SPI.h>
#include <Ethernet.h>
#include "plotly_streaming_ethernet.h"

// I change my tokens and API keys to something generic
// Plot.ly Tokens: 

#define nTraces 4


char *tokens[nTraces] = {"tokens1", "tokens2", "tokens3", "tokens4"};
// arguments: username, api key, streaming token, filename
plotly graph("Hohokam337", "API_KEYZ", tokens, "TITLE", nTraces);


byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
byte my_ip[] = { 199, 168, 1, 177 }; // google will tell you: "public ip address"

void startEthernet(){
    Serial.println("... Initializing ethernet");
    if(Ethernet.begin(mac) == 0){
        Serial.println("... Failed to configure Ethernet using DHCP");
        // no point in carrying on, so do nothing forevermore:
        // try to congifure using IP address instead of DHCP:
        Ethernet.begin(mac, my_ip);
    }
    Serial.println("... Done initializing ethernet");
    delay(1000);
}


void setup() {
  graph.maxpoints = 100;
  // Open serial communications and wait for port to open:
  Serial.begin(9600);

  startEthernet();
  
  graph.fileopt="overwrite";
  bool success;
  success = graph.init();
  if(!success){while(true){}}
  graph.openStream();
}

int SV, WV;

void loop() {
 
float SI = 0;{
  for(int i = 0; i < 1000; i++) {
    SI = SI + (.0264 * analogRead(A0) -13.51) / 1000;}
}
float WI = 0;{
  for(int i = 0; i < 1000; i++) {
    WI = WI + (.19 * analogRead(A0) -25) / 1000; }
}

  SV = (analogRead(A0)*.239);
  WV = (analogRead(A3)*.325);
  graph.plot(millis(), SV, tokens[0]);
  graph.plot(millis(), SI, tokens[1]);
  graph.plot(millis(), WV, tokens[2]);
  graph.plot(millis(), WI, tokens[3]);

}

When I run this I get there error:

C:\Program Files (x86)\Arduino\libraries\plotly_streaming_ethernet\plotly_streaming_ethernet.cpp:6:25: fatal error: avr/dtostrf.h: No such file or directory

 #include <avr/dtostrf.h>

Now I saw that this issue was covered for earlier Arduino editions but none of the solutions have worked for me.
Any help will be greatly appreciated.

Hohokam