spack mpich version issue on Ares

[candiceT233]

When installing hermes_shm in Ares spack install hermes_shm@master, the default version mpich@3.3.2 shows the below issue during configure phase:

...
     6935    configure.ac:421: warning: The macro `AC_TRY_RUN' is obsolete.
  >> 6936    configure.ac:421: You should run autoupdate.
  >> 6937    ./lib/autoconf/general.m4:2997: AC_TRY_RUN is expanded from...
  >> 6938    configure.ac:421: the top level
     6939    configure.ac:412: warning: The macro `AC_TRY_RUN' is obsolete.
  >> 6940    configure.ac:412: You should run autoupdate.
  >> 6941    ./lib/autoconf/general.m4:2997: AC_TRY_RUN is expanded from...
  >> 6942    configure.ac:412: the top level
     6943    configure.ac:403: warning: The macro `AC_TRY_RUN' is obsolete.
  >> 6944    configure.ac:403: You should run autoupdate.
  >> 6945    ./lib/autoconf/general.m4:2997: AC_TRY_RUN is expanded from...
  >> 6946    configure.ac:403: the top level
     6947    configure.ac:448: warning: The macro `AC_TRY_COMPILE' is obsolete.
  >> 6948    configure.ac:448: You should run autoupdate.
  >> 6949    ./lib/autoconf/general.m4:2847: AC_TRY_COMPILE is expanded from...
  >> 6950    configure.ac:448: the top level
     6951    configure.ac:444: warning: The macro `AC_TRY_COMPILE' is obsolete.
  >> 6952    configure.ac:444: You should run autoupdate.
  >> 6953    ./lib/autoconf/general.m4:2847: AC_TRY_COMPILE is expanded from...
  >> 6954    configure.ac:444: the top level
     6955    configure.ac:440: warning: The macro `AC_TRY_COMPILE' is obsolete.
  >> 6956    configure.ac:440: You should run autoupdate.
  >> 6957    ./lib/autoconf/general.m4:2847: AC_TRY_COMPILE is expanded from...
  >> 6958    configure.ac:440: the top level
...

To resolve: Change the depending version to mpich@3.4.3