added simple test
expect: added json_not_contains
assert: fixed assert_not_in method
Update expect.py
temporary
general: added generalized error message
Merge branch 'devel' of github.com:actionless/wooper into devel
expect: use more common exception
expect: fixed attribute set
fixed compatibility with slask client response
use response object in expectations instead of context one
expect: fixed headers-rlated methods
expect: headers: typo