[CI] pin datalad version

sprenger · sprenger · commit a25f517f3d43 · 2021-09-29T10:05:42.000+02:00
Datalad version 0.15.0 and later requires a git-annex version that is not in the ubuntu default packages yet. See also datalad/datalad@315911c
diff --git a/requirements_testing.txt b/requirements_testing.txt
@@ -1,6 +1,6 @@
 pytest
 pytest-cov
-datalad
+datalad==0.14.8  # 0.15. is incompatible with default apt git-annex version
 scipy>=1.0.0
 h5py
 igor
