fixed parser conflicts.
Merge branch 'conflictless-parser'
Added Decls module to ast, refined grammar to reflect new ast, does not compile
updated decl definitions, updated lexer, doesn't compile
Merge branch 'master' of code.seas.harvard.edu:matkit/matkit
Added Decl.ml
Added functions to decl.mli and decl.ml, can't compile
Added decl.ml and decl.mli to tracked files
decl module compiles, haven't used it for testing
Added (very) basic testing to see if decl.ml types
Added test_decl.ml to tracked files
Modified testing for parser, added some decl tests
fixed typing branch - it now compiles.
refactored Decl module.
Merge branch 'master' of code.seas.harvard.edu:matkit/matkit
renamed Env -> Ctx due to the conflicts.
further enhanced Decl module.
Merge branch 'master' of code.seas.harvard.edu:~ivg/matkit/matkit

Conflicts:
	src/ast.ml
	src/decl.ml
	src/decl.mli
	src/tests/test_decl.ml
updated gitignore
fixed test parsing.