Exclude non-essential files from dist package

.gitattributes

@@ -7,3 +7,6 @@
 *.json  text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
 *.test  text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=4
 *.yml   text eol=lf whitespace=blank-at-eol,blank-at-eof,space-before-tab,tab-in-indent,tabwidth=2
+
+# Exclude non-essential files from dist
+/tests export-ignore