Update HTTP Host test and Experimental tests

This branch contains some tests that were used to generate the reports in UZ and TM (https://ooni.torproject.org/reports/0.1/UZ/, https://ooni.torproject.org/reports/0.1/TM/).

Highlights:

* Add four new methods to the HTTP Host test (for more details see: https://github.com/TheTorProject/ooni-spec/blob/f4b1888a55f134c0e7b26259dbc152d4dca3130d/test-specs/ts-003-httphost.md)

* Add some experimental tests that test the presence of squid, do the same measurements of the HTTP Host test, but by talking to a TCP echo server.

* Remove superflous input file parameter option in HTTP invalid request line test