Feature/aggregator

[rhayes777]

• Group pickles into a directory
• Filter aggregator using inequalities

# Filtering based on inequalities
aggregator = aggregator.filter(aggregator.child.value > 1.0)

# Filtering using combinations
aggregator = aggregator.filter(
    aggregator.property.contains("a") & aggregator.contains("b")
)
aggregator = aggregator.filter(
    aggregator.property.contains("a") | aggregator.contains("b")
)