Ignoring all other test directories as well

Author: gsherwood

.gitattributes

@@ -1,3 +1,10 @@
 /tests export-ignore
+/CodeSniffer/Standards/Generic/Tests export-ignore
+/CodeSniffer/Standards/MySource/Tests export-ignore
+/CodeSniffer/Standards/PEAR/Tests export-ignore
+/CodeSniffer/Standards/PSR1/Tests export-ignore
+/CodeSniffer/Standards/PSR2/Tests export-ignore
+/CodeSniffer/Standards/Squiz/Tests export-ignore
+/CodeSniffer/Standards/Zend/Tests export-ignore
 .travis.yml export-ignore
 package.xml export-ignore