Unit Test BST in Java
Your tests seem to be of appropriate size and scope but there are a couple things I'd address.  

Assertions
First and foremost I don't see your code asserting on anything.
You manipulate the binarySearch tree, which is the first step, but then you don't check the state of it afterward.  As a reviewer I'd ask "what are your tests actually testing?"

Magic numbers
It's clear you thought about what each test was supposed to accomplish but the intent of the test could be clearer to the reader.  You could try adding meaning to the numbers you are inserting to the tree, adding comments, or some other way of making the purpose of each test very clear to the reader.