Added new SAS keywords (#1784)

This adds the SAS keywords libname, set, output, and options to the language definition.

components/prism-sas.js

@@ -26,7 +26,7 @@ Prism.languages.sas = {
 		pattern: /(["'])(?:\1\1|(?!\1)[\s\S])*\1/,
 		greedy: true
 	},
-	'keyword': /\b(?:data|else|format|if|input|proc\s\w+|quit|run|then)\b/i,
+	'keyword': /\b(?:data|else|format|if|input|proc\s\w+|quit|run|then|libname|set|output|options)\b/i,
 	// Decimal (1.2e23), hexadecimal (0c1x)
 	'number': /\b(?:[\da-f]+x|\d+(?:\.\d+)?(?:e[+-]?\d+)?)/i,
 	'operator': /\*\*?|\|\|?|!!?|¦¦?|<[>=]?|>[<=]?|[-+\/=&]|[~¬^]=?|\b(?:eq|ne|gt|lt|ge|le|in|not)\b/i,

tests/languages/sas/keyword_feature.test

@@ -1,13 +1,15 @@
 data else format if
 input proc run then
+libname set output options
 
 ----------------------------------------------------
 
 [
 	["keyword", "data"], ["keyword", "else"], ["keyword", "format"], ["keyword", "if"],
-	["keyword", "input"], ["keyword", "proc run"], ["keyword", "then"]
+	["keyword", "input"], ["keyword", "proc run"], ["keyword", "then"], ["keyword", "libname"],
+	["keyword", "set"], ["keyword", "output"], ["keyword", "options"]
 ]
 
 ----------------------------------------------------
 
-Checks for all keywords.
+Checks for all keywords.