Added new file validator, updated README and LICENSE

Author: Zachary Norman

LICENSE.txt

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-(c) 2018 Harris Geospatial Solutions, Inc.
+Copyright (c) 2018 Harris Geospatial Solutions, Inc.
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -8,6 +8,8 @@ Routine that can be used to perform input validation for any routine to ensure t
 
 - number   : If set, value supplied must be a number.
 
+- file     : If set, the value must represent a valid file on disk.
+
 This routine uses IDL's `isa` function to make the comparison so, in addition to the types above, you can specify anything else that can pass as an argument to the `isa` routine. Some additional examples of types are are: byte, int, long, float, hash, orderedhash, enviraster, graphicswin. The addition arguments can be any IDL-specific data type or it can also be the type of object such as idlgrwindow or any named, custom object.
 
 ## Examples
@@ -36,6 +38,6 @@ inputValidator, hash('nameOfArg', ['double', 'array'])
 
 ## License
 
-(c) 2018 Harris Geospatial Solutions, Inc.
+Copyright (c) 2018 Harris Geospatial Solutions, Inc.
 
 Licensed under MIT, see LICENSE.txt for more details.

inputvalidator.pro

@@ -71,7 +71,7 @@
 ;     an existing variable from something like a hash so you can print the term
 ;     "Key" which is the correct term. 
 ;
-; :Author: Zachary Norman - GitHub : znorman-harris
+; :Author: Zachary Norman - GitHub : [znorman-harris](https://github.com/znorman-harris)
 ;-
 pro inputValidator, requirements,$
   CALLED_FROM = called_from,$
@@ -132,6 +132,7 @@ pro inputValidator, requirements,$
     required = 0
     array = 0
     number = 0
+    file = 0
 
     ;flag for if we need all data types specified to be present
     ;otherwise just need one
@@ -156,6 +157,7 @@ pro inputValidator, requirements,$
         'required' : required = 1
         'array'    : array = 1
         'number'   : number = 1
+        'file'     : file = 1
         'all'      : all = 1
 
         else:begin
@@ -197,6 +199,13 @@ pro inputValidator, requirements,$
       endif
     endif
 
+    ;check for file
+    if (file) then begin
+      if ~file_test(value) then begin
+        message, pName + ' "' + varPrint + '" is not a file on disk, required!', LEVEL = scopeLevel
+      endif
+    endif
+    
     ;check for number
     if (number) then begin
       nflag = isa(value, /NUMBER)