[Fix 177]: Throw exception when spec version is not recognized by rea…

…der (microsoft#181)

Throwing OpenApiUnsupportedSpecVersionException when spec version is not recognized in Reader

Fix microsoft#172: Adding spec version to OpenApiDiagnostic of Reader (…

…microsoft#175)

update the version to 009

Merge pull request microsoft#144 from Microsoft/dm/housekeeping

Updates to the Readme along with examples