'millis' was not declared in this scope

[zoltangbereczky]

Veryfing code using this library in Particle Build fails with this error:

HttpClient/HttpClient.cpp:172:37: error: 'millis' was not declared in this scope
     unsigned long lastRead = millis()
HttpClient/HttpClient.cpp:231:22: error: 'delay' was not declared in this scope
             delay(200);
HttpClient/HttpClient.cpp:266:47: error: 'atoi' was not declared in this scope
             aResponse.status = atoi(statusCode.c_str());

[ilessiivi]

I ran into this problem myself and as suggested here, HttpClient.h needs to have #include "application.h" in order to work on Photons. I created the pull request #20 for this.