makeRequest method to modify url and method

[yawningphantom]

#901 This PR enables us to modify the url and the http method for every request. The url change was easy but to enable the http method change I had to change the sendRequest method as it is always sending the body in the request and when you do it for a GET request it throws up a type error TypeError: Request with GET/HEAD method cannot have body here hence I had to change the implementation of sendRequest I would recommend that we call the makeRequest method inside the sendRequest itself so that we can create the Request object dynamically and this can be modified.

[apollo-cla]

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[yawningphantom]

@trevor-scheer any update on this PR?