Rename contract capabilities property to provides

This lines up better with the original specification and how contracts
are being used by the OS

Change-type: minor

lib/contract.ts

@@ -648,8 +648,8 @@ export default class Contract {
 			// the list of hashes we should check against.
 			const match = matches(omit(matcher.raw.data, ['slug', 'version']));
 			const versionMatch = matcher.raw.data.version;
-			if (contract.raw.capabilities) {
-				for (const capability of contract.raw.capabilities) {
+			if (contract.raw.provides) {
+				for (const capability of contract.raw.provides) {
 					if (match(capability)) {
 						if (versionMatch) {
 							if (valid(capability.version) && validRange(versionMatch)) {
@@ -1290,6 +1290,7 @@ export default class Contract {
 		for (const conjunct of conjuncts) {
 			// (3-4) stop looking if an unsatisfied requirement is found
 			if (!this.isRequirementSatisfied(conjunct, options)) {
+				console.log('NOT SATISFIED', JSON.stringify(conjunct));
 				return false;
 			}
 		}

tests/contract/satisfies-child-contract.spec.ts

@@ -769,6 +769,60 @@ describe('Contract satisfiesChildContract', () => {
 		).to.be.true;
 	});
 
+	it('should return true given two fulfilled requirements from a context declaring capabilities with `provides`', () => {
+		const container = new Contract({
+			type: 'foo',
+			slug: 'bar',
+		});
+
+		const contract1 = new Contract({
+			type: 'meta.context',
+			slug: 'test',
+			provides: [
+				{
+					type: 'sw.os',
+					slug: 'debian',
+					version: 'wheezy',
+				},
+				{
+					type: 'arch.sw',
+					slug: 'amd64',
+					version: '1',
+				},
+			],
+		});
+
+		container.addChild(contract1);
+
+		expect(
+			container.satisfiesChildContract(
+				new Contract({
+					name: 'Node.js',
+					slug: 'nodejs',
+					type: 'sw.stack',
+					requires: [
+						{
+							slug: 'debian',
+							type: 'sw.os',
+						},
+						{
+							or: [
+								{
+									slug: 'amd64',
+									type: 'arch.sw',
+								},
+								{
+									slug: 'i386',
+									type: 'arch.sw',
+								},
+							],
+						},
+					],
+				}),
+			),
+		).to.be.true;
+	});
+
 	it('should return false given one unfulfilled requirement from a context with a composite contract', () => {
 		const container = new Contract({
 			type: 'foo',