Improve error message when using oneOf validation

[robframpton]

When using oneOf validation for a Component property, I would like the error message to display the valid types.

This is what is currently displayed.

Error: Warning: Invalid state passed to 'type'. Expected one of given values. Passed to 'MyComponent'.

This is what I'd like to see.

Error: Warning: Invalid state passed to 'type'. Expected one of the following values: 'value1', 'value2', 'value3'. Passed to 'MyComponent'.

[robframpton]

@mthadley @bryceosterhaus, as you guys have used these kind of validators a lot, what do you think?

[mthadley]

Sounds like an awesome improvement to me. Since any type can appear in oneOf, we should also make sure developers don't end up with something like this in their console:

Expected one of the following values: '[object Object]', '[object Object]', '[object Object]'.

[jbalsas]

This has already been merged into develop!