Update pull request template, Update conda_macos debug flag (#484)

Update pull request template to ask for additional information about the PR. This information can and will be used during the squash merge process to produce more useful commit logs.

Update Macros.conda_macos to remove ffpe-trap=invalid from debug flags.
This flag causes nf90_create to fail with the latest version of
the conda environment. This happens when debug flags are on
and a test with netcdf is turned on. I believe this is a compiler error.

.github/PULL_REQUEST_TEMPLATE.md

@@ -26,4 +26,4 @@ please refer to: <https://github.com/CICE-Consortium/About-Us/wiki/Resource-Inde
     - [ ] No, does the documentation need to be updated at a later time?
         - [ ] Yes
         - [ ] No 
-- [ ] Please provide any additional information or relevant details below:
+- [ ] Please document the changes in detail, including _why_ the changes are made.  This will become part of the PR commit log.

configuration/scripts/machines/Macros.conda_macos

@@ -14,7 +14,9 @@ FFLAGS     := -fconvert=big-endian -fbacktrace -ffree-line-length-none
 
 # Additional flags for the Fortran compiler when compiling in debug mode
 ifeq ($(ICE_BLDDEBUG), true)
-  FFLAGS   += -O0 -g -fcheck=bounds -finit-real=nan -fimplicit-none -ffpe-trap=invalid,zero,overflow
+# new version of conda gnu compiler has a bug in ffpe-trap=invalid with nf90_create
+#  FFLAGS   += -O0 -g -fcheck=bounds -finit-real=nan -fimplicit-none -ffpe-trap=invalid,zero,overflow
+  FFLAGS   += -O0 -g -fcheck=bounds -finit-real=nan -fimplicit-none -ffpe-trap=zero,overflow
 else
   FFLAGS   += -O2
 endif