jasmine: initial release improvements

* Fixes recursive discovery of the *.spec.js files.

Signed-off-by: Adrian Pawel Baran <adrian.pawel.baran@cern.ch>
Shouldn't the regular expression be `html_pattern = re.compile(".*\.html$")` to *NOT* match `foo/bar.html.js`?

Maybe it's enough to write the check in following way:
```python
mimetype = ("text/html" if specpath.endswith(".html") else
            "application/javascript")
```