Checking response body with a query language

[bkielbasa]

Is your feature request related to a problem? Please describe.

It is very common to check the content of the response. Right now, the only way of checking is making sure the response is a valid JSON.

For the query language, I found a few examples:

• JsonQuery -> $.array[?(@.key==2)].dictionary.a
• JSONPath -> x.store.book[0].title
• JSON Pointer -> "/foo/0"

Here, we have to make two decisions:

• Which query language we want to use
• How the step should be named
  I have a proposal for the name:

Then the response contains "/foo/0"

[bkielbasa]

Abaddon because the testhttp package was removed from the main repo