Removed text 'for dictionary value' from the validation message for dict

[rwieckowski]

Removed additional text for messages created during dictionary validation to provide consistent messages with other schema types and clean user defined messages.

Now the user defined messages are not polluted with additional text.
Following code:

import voluptuous as v
validate = v.Schema({'one': msg('two', 'should be "two"')})
validate({'one': 'three'})

gives us

Traceback (most recent call last):
...
InvalidList: should be "two" @ data['one']

instead of

Traceback (most recent call last):
...
InvalidList: should be "two" for dictionary value @ data['one']

[alecthomas]

This text was explicitly chosen because without it the error message can be ambiguous, so I prefer not to merge as-is.

I wouldn't be opposed to a Schema-level option to enable this behaviour, though there are a bunch more places that need to be changed to make this consistent. For example, list/tuple validators have the same form and would also need to be updated.

Feel free to reopen this or send through another pull request if you continue.

[rwieckowski]

The problem is with dictionaries where returned message is concatenated with additional text. That text shows in my user-defined message, so I don't have full control on its final form.
Is the path not good enought to determine error location in case od dictionaries?

In case of list/tuples you doesn't have message concatenation so user-defined messages works fine here.

import voluptuous as v
validate = v.Schema(['one'])
validate(['two'])

gives us

Traceback (most recent call last):
...
InvalidList: invalid list value @ data[0]

And with user-defined message

import voluptuous as v

validate = v.Schema(v.msg(['one'], 'should be "one"'))
validate('two')

gives us (which is correct)

Traceback (most recent call last):
...
InvalidList: should be "one"

Also check example in the pull request which shows why the dictionary behaviours differently.