Fix git ignore

.gitignore

@@ -56,63 +56,6 @@ setup.log
 
 # Backup of opam lock file
 hazel.opam.locked.old
-_coverage/coverage.css
-_coverage/coverage.js
-_coverage/highlight.pack.js
-_coverage/index.html
-_coverage/src/haz3lcore/StructureShareSexp.re.html
-_coverage/src/haz3lcore/VarMap.re.html
-_coverage/src/haz3lcore/dynamics/Builtins.re.html
-_coverage/src/haz3lcore/dynamics/Casts.re.html
-_coverage/src/haz3lcore/dynamics/Constraint.re.html
-_coverage/src/haz3lcore/dynamics/Delta.re.html
-_coverage/src/haz3lcore/dynamics/DHExp.re.html
-_coverage/src/haz3lcore/dynamics/DHPat.re.html
-_coverage/src/haz3lcore/dynamics/Elaborator.re.html
-_coverage/src/haz3lcore/dynamics/Environment.re.html
-_coverage/src/haz3lcore/dynamics/EvaluatorError.re.html
-_coverage/src/haz3lcore/dynamics/FilterAction.re.html
-_coverage/src/haz3lcore/dynamics/Incon.re.html
-_coverage/src/haz3lcore/dynamics/InvalidOperationError.re.html
-_coverage/src/haz3lcore/dynamics/Sets.re.html
-_coverage/src/haz3lcore/dynamics/VarBstMap.re.html
-_coverage/src/haz3lcore/lang/Form.re.html
-_coverage/src/haz3lcore/lang/Operators.re.html
-_coverage/src/haz3lcore/lang/Precedence.re.html
-_coverage/src/haz3lcore/lang/Sort.re.html
-_coverage/src/haz3lcore/lang/term/Any.re.html
-_coverage/src/haz3lcore/lang/term/Cls.re.html
-_coverage/src/haz3lcore/lang/term/Exp.re.html
-_coverage/src/haz3lcore/lang/term/IdTagged.re.html
-_coverage/src/haz3lcore/lang/term/Pat.re.html
-_coverage/src/haz3lcore/lang/term/Rul.re.html
-_coverage/src/haz3lcore/lang/term/TPat.re.html
-_coverage/src/haz3lcore/lang/term/Typ.re.html
-_coverage/src/haz3lcore/prog/CoreSettings.re.html
-_coverage/src/haz3lcore/statics/CoCtx.re.html
-_coverage/src/haz3lcore/statics/Constructor.re.html
-_coverage/src/haz3lcore/statics/ConstructorMap.re.html
-_coverage/src/haz3lcore/statics/Ctx.re.html
-_coverage/src/haz3lcore/statics/Info.re.html
-_coverage/src/haz3lcore/statics/Mode.re.html
-_coverage/src/haz3lcore/statics/Self.re.html
-_coverage/src/haz3lcore/statics/Statics.re.html
-_coverage/src/haz3lcore/statics/Term.re.html
-_coverage/src/haz3lcore/statics/TermBase.re.html
-_coverage/src/haz3lcore/statics/Var.re.html
-_coverage/src/haz3lcore/statics/uterm/UExp.re.html
-_coverage/src/haz3lcore/statics/uterm/UPat.re.html
-_coverage/src/haz3lcore/statics/uterm/UTyp.re.html
-_coverage/src/haz3lcore/tiles/Id.re.html
-_coverage/src/haz3lcore/tiles/Mold.re.html
-_coverage/src/haz3lcore/tiles/Nib.re.html
-_coverage/src/haz3lcore/tiles/Nibs.re.html
-_coverage/src/haz3lcore/tiles/Secondary.re.html
-_coverage/src/haz3lcore/tiles/Token.re.html
-_coverage/src/util/Direction.re.html
-_coverage/src/util/IntMap.re.html
-_coverage/src/util/ListUtil.re.html
-_coverage/src/util/OptUtil.re.html
-_coverage/src/util/StringUtil.re.html
-_coverage/src/util/TupleUtil.re.html
-_coverage/src/util/Util.re.html
+
+# Code coverage
+_coverage/