Library Fixes (#127)

* Removing warnings

* handle reading zero-length packets

* updating travis to exclude archived libraries, addin Arduino WiFi101 lib instead

* adding esp lib to travis

* restrict builds to current hardware platforms

* travis, esp8266: skip esp target for non-esp-based examples

* adding test skips for zero, fixing fingerprint error

bump library version

examples/adafruitio_errors_esp8266/.zero.test.skip

@@ -0,0 +1 @@
+