Add more integration tests

[sdelatorrep]

Add more tests to JMeter project.
The goal of these tests is to verify that a deployed beacon is compliant with v0.4. Among others things:

• Test mandatory fields
• Test all features are working (e.g. SV, range queries, etc.)
  • Question: what happens if a beacon decides to not implement something?
• Also consider issue Incomplete tests #5

These tests should query the fake dataset provided with the implementation (see Quick start) so we can be sure of the content of the response.