Temporary pin to avoid problems caused by Proj4 v5.1. (#3150)

pp-mo · web-flow · commit 2b6b7870e346 · 2018-08-31T16:28:59.000+01:00
diff --git a/requirements/core.txt b/requirements/core.txt
@@ -4,6 +4,7 @@
 # Without these, iris won't even import.
 
 cartopy
+#conda: proj4<5
 cf_units>=2
 cftime
 dask[array]==0.18.1  #conda: dask==0.18.1
