Fix travis builds, add esp32 builds

[liebman]

Use current arduino version in builds.
Add esp32 platform builds excluding two examples due to SPIFFS incompatibility:

• "AutoConnectWithFSParametersAndCustomIP.ino"
• "AutoConnectWithFSParameters.ino"

Disabled the "codecov.io" support as no coverage is generated.

[liebman]

That's odd, this ran correctly on my fork! I'll make a small change to try again.

https://travis-ci.org/liebman/WiFiManager/builds/356041054

[tablatronix]

I am not to hip on the travis, asking tzapu to sign off on this.
Looks good to me

[liebman]

Actually its failing correctly! on esp32 we get this:

/Users/chris.l/Arduino/libraries/WiFiManager/WiFiManager.cpp: In member function 'boolean WiFiManager::stopConfigPortal()':
/Users/chris.l/Arduino/libraries/WiFiManager/WiFiManager.cpp:582:20: error: expected primary-expression before ',' token
   if(!ret)DEBUG_WM(,DEBUG_ERROR,F("[ERROR] disconnect configportal - softAPdisconnect FAILED"));
                    ^

I just replicated this with an example in Eclipse/Sloeber by updating my fork form the current development branch.....

[tablatronix]

Sorry about that I forgot to push

[liebman]

Passed!!!!

[tablatronix]

Thats what happens when you code while watching youtube...

[tablatronix]

#531
#521

[tablatronix]

fix esp32 examples
7279333