To better fit with our current CI processes, use git to clone the
suricata-update and libhtp dependencies. The requirements.txt file has
been modified to take a repo URL and a `-b` command line option for tag
or branch.
For the master branch we will use the libhtp 0.5.x branch and the
suricata-update master branch.
Also allows for repo and branch names to be overrided with environment
variables:
- SU_REPO
- SU_BRANCH
- LIBHTP_REPO
- LIBHTP_BRANCH
Add a bundle.sh script to bundle the requirements of libhtp
and suricata-update. This uses a Python like requirements.txt
file to specify the URL to download for libhtp and suricata-update.