travis fix

new Typescript version & support for native SPARQL protocol

move to sparql-engine@0.5.1

fix invalid time reprtong

sparql-engine up to 0.5.0, with support for SPARQL property paths

fix an issue with LIMIT queries

updated sparql-engine to v0.3.2

use sparql-engine v0.2.1

fix invalid webpack bundles

uppgrade to sparql-engine v0.2.0