feature(organization): add isMember api

Closes #289

Author: clayreimann

lib/Organization.js

@@ -45,6 +45,16 @@ class Organization extends Requestable {
       return this._requestAllPages(`/orgs/${this.__name}/repos`, requestOptions, cb);
    }
 
+   /**
+    * Query if the user is a member or not
+    * @param {string} username - the user in question
+    * @param {Requestable.callback} [cb] - will receive true if the user is a member
+    * @return {Promise} - the promise for the http request
+    */
+   isMember(username, cb) {
+      return this._request204or404(`/orgs/${this.__name}/members/${username}`, null, cb);
+   }
+
    /**
     * List the users who are members of the company
     * @see https://developer.github.com/v3/orgs/members/#members-list

test/organization.spec.js

@@ -8,6 +8,7 @@ import getTestRepoName from './helpers/getTestRepoName';
 describe('Organization', function() {
    let github;
    const ORG_NAME = 'github-tools';
+   const MEMBER_NAME = 'clayreimann';
 
    before(function() {
       github = new Github({
@@ -34,12 +35,20 @@ describe('Organization', function() {
             .then(function({data: members}) {
                expect(members).to.be.an.array();
 
-               let hasClayReimann = members.reduce((found, member) => member.login === 'clayreimann' || found, false);
+               let hasClayReimann = members.reduce((found, member) => member.login === MEMBER_NAME || found, false);
                expect(hasClayReimann).to.be.true();
 
                done();
             }).catch(done);
       });
+
+      it('should test for membership', function(done) {
+         organization.isMember(MEMBER_NAME)
+            .then(function(isMember) {
+               expect(isMember).to.be.true();
+               done();
+            }).catch(done);
+      });
    });
 
    describe('creating/updating', function() {