Don't include development related files in distribution package (#307)

AppVeyor fail is unrelated

Author: heelc29

.gitattributes

@@ -1,10 +1,13 @@
 .github/ export-ignore
-.travis/ export-ignore
+.phan/ export-ignore
+docs/ export-ignore
 Tests/ export-ignore
 .appveyor.yml export-ignore
+.drone.jsonnet export-ignore
+.drone.yml export-ignore
+.editorconfig export-ignore
 .gitattributes export-ignore
 .gitignore export-ignore
-.travis.yml export-ignore
-phpunit.appveyor.xml export-ignore
+phpunit.*.xml.dist export-ignore
 phpunit.xml.dist export-ignore
 ruleset.xml export-ignore