TESTING.md: Add it

Author: t-b

TESTING.md

@@ -0,0 +1,29 @@
+# Testing
+
+The tests in the `tests` folder use pytest and can be run locally as:
+
+```
+SKIP_LIMS=true TEST_INHOUSE=false pytest
+```
+
+This does not assume that you have access to AllenInstitute internal resources like LIMS or network shares.
+
+## Strategy for adopting newer NWB schema versions
+
+The upstream source of NWB files for ipfx is [MIES](https://github.com/AllenInstitute/MIES) and
+[IPNWB](https://github.com/AllenInstitute/IPNWB). We are at the moment using fixed versions of nwb-schema for
+IPNWB and pynwb for ipfx. This is done in order to reduce maintenance and friction between the two.
+
+Steps for upgrading:
+
+- Choose a pynwb/nwb-schema version you want to adopt
+- Raise pynwb version in `requirements.txt`
+- Check if all tests still pass. In the past this always required patching the latest
+  pynwb version, bringing that patch upstream and waiting for a new release.
+- Fix pynwb deprecations where appropriate
+- Upgrade the nwb-schema version used in IPNWB as documented there
+- Re-export the files `Vip-IRES-Cre;Ai14(IVSCC)-226110.03.01.pxp` and
+  `Vip-IRES-Cre;Ai14(IVSCC)-236654.04.02.pxp` using the IPNWB/MIES version with the new nwb-schema to NWBv2
+- Add the files to `tests/data` and extend `testdata` in `tests/test_run_feature_vector.py` with them
+- Check if the tests still pass
+- Propose a PR