Evalai: Add ^ & $ in regex of urls for proper matching

[HargovindArora]

' ^ ' sign should be introduced in the regular expressions of the url's, mentioned in the url files so that our search is always matched up correctly.

For example:
If we have not added the initial caret character (i.e., 'hello/$'), Django would match any URL that ends with hello/, such as /my/site/hello/.
Also it will be more syntactically correct.

[guyandtheworld]

@HargovindArora Can I take this up?

[HargovindArora]

Hey, @isht3 I was interested to do this on my own and also it will give me some experience of the code base. Would you mind if I do this? :)

[guyandtheworld]

@HargovindArora Haha, cool! I'll close my PR. :)