CircleCi - active but failing

[0xc0170]

An example from the latest PR, which just adds a new target, the CI fails - https://circleci.com/gh/ARMmbed/mbed-ls/76

[rainierwolfcastle]

ARM Internal Ref: IOTSYST-575

[PrzemekWirkus]

It fails because OS on CircleCI instance is not detected by mbed-ls.
This will be soon fixed with Generic Linux support via one of the existing external PRs.

[PrzemekWirkus]

Fixed with #26