Dgraph v0.7.3 release

Features:

• Support shortest path query
• Support storing and retrieving edge attributes
• Support aggregation functions (min, max, sum)
• Support password data type
• Support Dynamic schema.
• Support filter by count
• Support sorting and pagination at root.
• Support user interface to query and visualize results from Dgraph.
• Support normalize directive in query
• Support specifying tokenizer in schema file
• Graceful shutdown of Dgraph.

Improvements:

• Stricter check for invalid keywords while querying.
• Use block lists instead of a slice for task.List.
• Get debug info using a query parameter.

Bug fixes:

• Remove duplicate results when using order on an indexed predicate.
• Fix watermark is nil.