Feature: basic auth

[benbusby]

Username/password can be set either as Dockerfile build arguments or
passed into the run script as "--userpass username:password"

Closes #43

[ilovepancakes95]

First, I am totally fine with the basic auth implementation as opposed to a more complicated login page/user system, but is there a way to make it so it remembers/caches my login between browser launches? If I set whoogle as my default search engine in firefox for example, everytime I launch the browser I have to re-login to perform search which gets quite cumbersome after a whole day or working and searching. At the very least, I tried to get firefox to remember and autofill the username/password but it doesn't seem to work with the type of auth form whoogle uses. I want to run whoogle on a VPS but also want to protect it from unauthorized use and getting hammered by bots/other people if they find it, yet want my devices I add whoogle to easily access and keep using it seamlessly.

@benbusby Second, how so we buy you a pack of beer or some pizzas? Seriously, every decent feature people keep requesting here seems to be implemented within a week, and it's much appreciated. Job well done on this project.