minor #695 Enhancement: Add more files to .gitattributes file (OskarStark)

This PR was merged into the 1.0-dev branch.

Discussion
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Enhancement: Add more files to .gitattributes file

These files are not necessary in a released version

Commits
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42f5071 Enhancement: Add more files to .gitattributes file

Author: weaverryan

.gitattributes

@@ -1 +1,5 @@
+.* export-ignore
+*.md export-ignore
+appveyor.yml
+phpunit.xml.dist
 /tests export-ignore