Add second param to check funcs to match user id

Refer #15
Update docs and examples to add business rules
Update admittance to check bus. rule expressions
Update example file to demonstrate expressions
Update docs, fix errors and add expressions docs
Add test and code to handle numeric string params
Factor out is function for reusability
Remove spaces to match file formatting
Merge pull request #16 from digitalsadhu/add/basic_business_rule_checking#15

Add/basic business rule checking#15