Update submodule ecl to latest Mon May 7 20:26:31 CDT 2018

    - ecl in PX4/Firmware (076160d): PX4/PX4-ECL@372f9f4
    - ecl current upstream: PX4/PX4-ECL@b227aca
    - Changes: PX4/PX4-ECL@372f9f4...b227aca

    b227aca 2018-05-05 Daniel Agar - geo_lookup fix table bounds
e494a4e 2018-05-05 Daniel Agar - Jenkins set git username and email with environment variables
3639087 2018-05-05 Daniel Agar - cmake and Jenkins add basic address santiizer test buld
1fba622 2018-05-05 Daniel Agar - travis-ci basic build script
cde2ee9 2018-05-05 Daniel Agar - cmake ignore missing-field-initializers
2100127 2018-05-05 Daniel Agar - geo: zeroing static unnecessary
0f12db5 2018-05-03 Daniel Agar - travis-ci enable coverity_scan
aceab8c 2018-05-05 Daniel Agar - Jenkins upload coverage to codecov.io
5780cd3 2018-05-05 Daniel Agar - Jenkins create PX4/Firmware test branch and push (#436)
cf957b5 2018-05-04 Daniel Agar - code coverage cmake and Jenkins support
4e0cd45 2018-05-03 Daniel Agar - doxygen cmake and Jenkins support