Give a better error message on received expectations with args

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Add a changelog entry for #269

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Drop length checking, first gives nils when empty.

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Add a spec that tests we don't gsub [ for ( for array arguments.

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Remove some uneeded string mutation in the error generator

Signed-off-by: Sam Phippen <samphippen@googlemail.com>
Merge pull request #269 from samphippen/better-received-messages-args

Give a better error message on received expectations with args