Remove upper case constants (flutter#17)

* Remove usage of upper-case constants.

* update SDK version
* Remove 1.23.0 from travis config.

.travis.yml

@@ -2,8 +2,6 @@ language: dart
 
 dart:
   - dev
-  - stable
-  - 1.23.0
 
 dart_task:
   - test: --platform vm

CHANGELOG.md

@@ -1,6 +1,6 @@
 ## 3.1.2
 
-* Require Dart SDK 1.23 or greater.
+* Require Dart SDK 2.0.0-dev.17.0 or greater.
 
 * A number of strong-mode fixes.
 

pubspec.yaml

@@ -5,7 +5,7 @@ homepage: https://github.com/dart-lang/http_parser
 description: >
   A platform-independent package for parsing and serializing HTTP formats.
 environment:
-  sdk: ">=1.23.0 <2.0.0"
+  sdk: ">=2.0.0-dev.17.0 <2.0.0"
 dependencies:
   charcode: "^1.1.0"
   collection: ">=0.9.1 <2.0.0"

test/http_date_test.dart

@@ -43,7 +43,7 @@ void main() {
       test("parses the example date", () {
         var date = parseHttpDate("Sun, 06 Nov 1994 08:49:37 GMT");
         expect(date.day, equals(6));
-        expect(date.month, equals(DateTime.NOVEMBER));
+        expect(date.month, equals(DateTime.november));
         expect(date.year, equals(1994));
         expect(date.hour, equals(8));
         expect(date.minute, equals(49));
@@ -147,7 +147,7 @@ void main() {
       test("parses the example date", () {
         var date = parseHttpDate("Sunday, 06-Nov-94 08:49:37 GMT");
         expect(date.day, equals(6));
-        expect(date.month, equals(DateTime.NOVEMBER));
+        expect(date.month, equals(DateTime.november));
         expect(date.year, equals(1994));
         expect(date.hour, equals(8));
         expect(date.minute, equals(49));
@@ -239,7 +239,7 @@ void main() {
       test("parses the example date", () {
         var date = parseHttpDate("Sun Nov  6 08:49:37 1994");
         expect(date.day, equals(6));
-        expect(date.month, equals(DateTime.NOVEMBER));
+        expect(date.month, equals(DateTime.november));
         expect(date.year, equals(1994));
         expect(date.hour, equals(8));
         expect(date.minute, equals(49));
@@ -250,7 +250,7 @@ void main() {
       test("parses a date with a two-digit day", () {
         var date = parseHttpDate("Sun Nov 16 08:49:37 1994");
         expect(date.day, equals(16));
-        expect(date.month, equals(DateTime.NOVEMBER));
+        expect(date.month, equals(DateTime.november));
         expect(date.year, equals(1994));
         expect(date.hour, equals(8));
         expect(date.minute, equals(49));