Configure appveyor (#142)

with much appreciation to @michaeltryby 🎉 

* Initial commit getting Appveyor running
* Modifying branch built
* Modifying generator
* Modifying path to test scripts
* Modifying path to test scripts
* Configuring appveyor cache to store cmake generated build files
* suppressing insecure string warnings
* Fixing typo
* Fixing problem with cmake build invocation
* Changing CMake to Linux build on Travis
* Adding compiler flags for MSVC
* Adding Appveyor build status badge
* Adding Appveyor build status badge
* Adding include directory so it is available to project files
* cleaning cache
* rebuilding cache

tools/gen-config.cmd

@@ -0,0 +1,29 @@
+::
+::  gen-config.cmd - Generated nrtest app configuration file for test executable
+::  
+::  Date Created: 1/8/2018
+::
+::  Author: Michael E. Tryby
+::          US EPA - ORD/NRMRL
+::
+::  Arguments: 
+::    1 - absolute path to test executable (valid path seperator for nrtest is "/")
+::
+
+@echo off
+setlocal
+
+:: process path to remove quotes and convert backward to forward slash
+set ABS_BUILD_PATH=%~1
+set ABS_BUILD_PATH=%ABS_BUILD_PATH:\=/%
+
+:: this is the target created by the cmake build script
+set TEST_CMD=runepanet.exe
+
+echo {
+echo     "name" : "epanet",
+echo     "version" : "",
+echo     "description" : "",
+echo     "setup_script" : "",
+echo     "exe" : "%ABS_BUILD_PATH%/%TEST_CMD%"
+echo }