Resolves #92

The problem

• There is a bug in the algorithm that processes the value of the attribute when it has reached an end quote
• If it has detected an end quote, it will automatically save the value of str.slice(attrObj.valueStarts, i) into attrObj.value
• However, attrObj.valueStarts may never have been defined if the attribute is an empty string ""
• Therefore, the value that gets saved is str.slice(undefined, i), which will is essentially str.slice(0, i). This saves the substring of str from the very start up to i

Solution

• Handle this case specifically, and reset the attrObj and quotes if the strings are empty

Screenshot of the failing test before the fix: