Add simple testcase for protocol filtering.

[janLo]

This adds a simple .ino to test protocol filtering. The test generates a pulse train and parses it five rounds with and without the protocol support limited. The output on the serial console will differ between the two parts:

First part:

Decoding turn 0

parsed message [elro_400_switch][] (0) {"systemcode":14,"unitcode":15,"state":"on"}
parsed message [elro_800_contact][] (0) {"systemcode":17,"unitcode":1,"state":"opened"}
parsed message [elro_800_switch][] (0) {"systemcode":17,"unitcode":1,"state":"on"}
parsed message [ev1527][] (0) {"unitcode":700331,"state":"closed"}
parsed message [pollin][] (0) {"systemcode":17,"unitcode":1,"state":"on"}

Second part:

Decoding turn 0

parsed message [elro_800_switch][] (3) {"systemcode":17,"unitcode":1,"state":"on"}

This is based on PR #19.

[puuu]

Thanks. Please see the limit branch:

• changed commit message
• separate commit for .travis.yaml
• clang-format

[janLo]

This is now part of PR #16