Merge branch 'master' of github.com:mapbox/rasterio

Update version and change log

Add shutil to list of modules to build from sdist

Update change log

Make our temp VRTs larger so we hit the source overviews properly

xfail for gdal < 2.1

Remove -W flag

Merge pull request rasterio#1073 from mojodna/warped-vrt-source-geore…

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Warped vrt source georeferencing

Update change log and version.

Update change log, version, authors