Added tests in UNITTESTS directory but not recognised with 'mbed status' command

First time posting a github issue and I feel like this is a rookie error I am making but here goes:

I have added unit test files under the mbed-os/UNITTESTS directory and am at the stage that I want to commit all my files and push. However, (I am using Mercurial) if I use the command :
`mbed status`
No changes have been detected.
Also,
`hg add`
doesn't detect any changes either.

If I look in the mbed-os directory I see a .gitignore file. Changing this to .hgignore and then running:
`mbed status`
Give the following:
```
[mbed] Working path "/home/zanev/mbed/AFDAU_0_01" (program)
[mbed] Status for "mbed-os":
D .gitignore
?? .hgignore
?? UNITTESTS/app/
?? UNITTESTS/bits.cpp
?? UNITTESTS/build/
```
However it isn't detecting the actual unit test .cpp & cmake files.