Simplified makefile

[bartnijssen]

Merge after PR #347

I propose that we simplify Part 0 of the makefile in the following way:

• delete the FC_ENV variable and the associated series of ifeq() statements that document the settings for different compilation environments. The reason is that this gets outdated quickly and it is difficult to maintain and navigate

• add INCLUDES and LIBRARIES variables that the user can set directly. E.g.

  INCLUDES = -I/usr/local/Cellar/netcdf/4.6.3_1/include -I/usr/local/Cellar/lapack/3.8.0_2/include
  LIBRARIES = -L/usr/local/Cellar/netcdf/4.6.3_1/lib -lnetcdff -L/usr/local/Cellar/lapack/3.8.0_2/lib -lblas -llapack

• perhaps add a page to the wiki where people can document the Part 0 of the Makefile that works for their settings.

• Recommend usage (as documented at the start of the Makefile)

  # Recommended use: Copy this file to Makefile.local, edit it to your 
  # heart's content, and then run `make -f build/Makefile.local` from
  # your top level SUMMA directory. Don't include the Makefile.local in
  # any pull requests you make.

Tested with build settings on OS X.

[arbennett]

In the old makefile the variables were all commented out by default, which allowed you to have them set directly in your environment. Like this:

$ export FC=gfortran
$ export F_MASTER=..
$ export FC_EXE=gfortran
$ make

I kind of like that this is possible, but don't use it myself. I think it would be nice to either make this possible, or make it easy to comment out all of the required lines easily.

[bartnijssen]

Note that sample configurations can be documented on the SUMMA wiki: https://github.com/NCAR/summa/wiki/SUMMA-Makefile-Part-0-configuration

[bartnijssen]

@arbennett : Changes made - it now passes the CI build. I also updated the Dockerfile and added some configurations that I have been using in: https://github.com/NCAR/summa/wiki/SUMMA-Makefile-Part-0-configuration

[bartnijssen]

Close issue #342 when merged