Change strange metaphor from Rome to Eiffel Tower

[banflam]

In the "Introduction to Compilers" section there is a line:

But Rome wasn’t built in a day … and neither is any serious software.

However, the photo attached is a cool photo of the Eiffel Tower under construction.

I changed the reference to "Rome" to the Eiffel Tower to better make the point and remove this inconsistency.

[pdarragh]

The phrase "Rome wasn't built in a day" is an established idiom in English, so I think altering the text doesn't make sense. Unfortunately, we have no photographs of the construction of Rome, so we settled for some other large-scale project. That the text and image don't exactly align is unideal but also not terribly critical, in my opinion, but I do appreciate the thought!