Move file for logisitic regression example

[agitter]

1041392 added an interactive logistic regression demo. We need to move the .js and .css files into the respective assets subdirectories, the data into the data subdirectory, and the HTML into the lesson. We'll need to update relative file paths after moving files.

[agitter]

a8ad8e0 5180d48 0f04fcd and f398327 are initial steps toward moving these files.

[agitter]

The interactive demo works, but I had to hard code file paths. I need to revert 5101fcc and fix the relative paths.