Use JUnit to unit test the new Java package

[mghosh00]

Here are a list of packages that need to be tested:

• [x] components
• [x] data_generators
• [x] functions
• [x] learning
• [x] util

[mghosh00]

Subtasks

• components

• [x] Edge

• [x] Layer

• [x] Network

• [x] Neuron

• data_generators

• [x] DataGenerator (abstract)

• [x] DataGenerator plotting method (once Plotter class is written)

• [x] NormalDataGenerator

• [x] UniformDataGenerator

• functions

• [x] Activator (interface)

• [x] CrossEntropyLoss

• [x] LeakyReLU

• [x] MSELoss

• [x] Sigmoid

• [x] Softmax

• [x] Transfer

• learning

• [x] Learner (abstract)

• [x] Tester

• [x] Trainer

• [x] Validator

• util

• [x] DataSplitter

• [x] Header (enum)

• [x] Partitioner

• [x] Plotter

• [x] WeightedPartitioner