Created a library from TinyDB

Hello kcochibili,

I just wanted to throw this out there I came across your java file and I really liked it. it cleans up alot of the annoying shared preferences lines of code. Plus it has a cool name. ( I created one myself but its in a utils class with a bunch of other methods ) Now I didn't know how far you were going to go with this project but I made it into a Android Studio Library so it can be pulled into a project with dependency management software. If you didn't want this I totally understand but if you wanted to make it a library here is all of the fun files that go around it.  

Also just made a few Edits

Edited a few lines of code getLong was returning an int so i changed
it to return a long.

When getting a double back there was a misspelling
theString was the name of the string and number was the name given in
Double.parse line of code so I changed them both to number.

Otherwise exact same code just created as a library instead of just a
file.

Cheers 
Aaron