Working on maps
Supporting map literal syntax
Merge branch 'maps' of https://github.com/lmcgrath/snacks-lang into maps

Conflicts:
	src/main/java/snacks/lang/SnacksMap.java
	src/main/java/snacks/lang/parser/Scanner.java
	src/main/java/snacks/lang/parser/syntax/SyntaxFactory.java
	src/main/resources/snacks.grammar
	src/test/java/snacks/lang/MapTest.java
Merge branch 'maps'

Conflicts:
	src/main/java/snacks/lang/SnacksMap.java
	src/test/java/snacks/lang/MapTest.java