Fixed powerOnOff timeout. Fixes #19

Merge pull request #7 from blemasle/features-esp32-compatibility

Platforms compatibitily enhancements

Merge pull request #5 from blemasle/features-optional-pins

Reduce required pin count

Merge pull request #4 from blemasle/bugfixes-httpstack-601

Fix the bearer configuration and GPRS initialization sequence

Updated arduino library properties