0.9.1 : Revamp session assertions

Maintenance release introducing the following changes.

• The session assertions have been redesigned to provide a unification with the JSON assertions which have been extracted for reuse - #86 .

You can now express the usual assertions available on the http body on any session key:

session_value("my-json-value").asJson.path("a.b.c").ignoring("d").is(...)

Two new helpers have also been added to test the existence of keys in the session:

  session_value("my-key").isPresent
  session_value("my-key").isAbsent

• A bug concerning the definition of custom body type has been fixed - #93

This is an advance feature that still needs a better documentation - #92