Fix stale references to `tests` directory (#3469)

Some of the benchmarks were failing due to references to files in the
`tests` directory, which is now called `test`.  A search found other
references to it also.  This commit updates all these references.

1 files changed, 4 insertions, 4 deletions

diff --git a/INSTALL.md b/INSTALL.md
index 9d03e14f3..ed34a95c9 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -281,10 +281,10 @@ the `-t` option:
 
 If you add a new feature to pandoc, please add tests as well, following
 the pattern of the existing tests. The test suite code is in
-`tests/test-pandoc.hs`. If you are adding a new reader or writer, it is
-probably easiest to add some data files to the `tests` directory, and
-modify `tests/Tests/Old.hs`. Otherwise, it is better to modify the module
-under the `tests/Tests` hierarchy corresponding to the pandoc module you
+`test/test-pandoc.hs`. If you are adding a new reader or writer, it is
+probably easiest to add some data files to the `test` directory, and
+modify `test/Tests/Old.hs`. Otherwise, it is better to modify the module
+under the `test/Tests` hierarchy corresponding to the pandoc module you
 are changing.
 
 ### Running benchmarks