Remove default Maven settings for Travis
Remove default Maven settings for Travis

The default settings use the GCS Maven Central mirror, which lately
has had long delays on updating after new artifacts are published.

dain/presto,losipiuk/presto,ebyhr/presto,ebyhr/presto,dain/presto,treasure-data/presto,electrum/presto,treasure-data/presto,Praveen2112/presto,Praveen2112/presto,erichwang/presto,martint/presto,electrum/presto,hgschmie/presto,losipiuk/presto,electrum/presto,ebyhr/presto,smartnews/presto,11xor6/presto,martint/presto,11xor6/presto,erichwang/presto,smartnews/presto,ebyhr/presto,smartnews/presto,Praveen2112/presto,smartnews/presto,dain/presto,smartnews/presto,treasure-data/presto,hgschmie/presto,electrum/presto,11xor6/presto,treasure-data/presto,ebyhr/presto,dain/presto,erichwang/presto,hgschmie/presto,martint/presto,Praveen2112/presto,dain/presto,losipiuk/presto,hgschmie/presto,martint/presto,losipiuk/presto,Praveen2112/presto,treasure-data/presto,treasure-data/presto,hgschmie/presto,losipiuk/presto,electrum/presto,11xor6/presto,erichwang/presto,martint/presto,11xor6/presto,erichwang/presto