[BUG] Curl Bash rule misses some forms of use

[loredous]

Describe the bug
In testing the curl bash rule, it was found that it does not catch the following:

curl -sSf https://build.travis-ci.org/files/rustup-init.sh | sh -s -- --default-toolchain=$TRAVIS_RUST_VERSION -y

To Reproduce
Steps to reproduce the behavior:

1. submit the above string to the service
2. Note that the results only include the dependency, but not a finding for the curl bash

Expected behavior
It should also note that this line is doing an un-verified curl bash