Refactor containers to share more code (#61)

Specifically, make sure that the header, footer, and tabs are all
shared code so that they look the same and don't need to be
redefined as we add more tab pages.

src/course-header/CourseTabsNavigation.jsx

@@ -1,17 +1,16 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import { injectIntl, intlShape } from '@edx/frontend-platform/i18n';
-import { getConfig } from '@edx/frontend-platform';
 import classNames from 'classnames';
 
 import messages from './messages';
 import Tabs from '../tabs/Tabs';
 
 function CourseTabsNavigation({
-  activeTabSlug, tabs, intl,
+  activeTabSlug, className, tabs, intl,
 }) {
   return (
-    <div className="course-tabs-navigation">
+    <div className={classNames('course-tabs-navigation', className)}>
       <div className="container-fluid">
         <Tabs
           className="nav-underline-tabs"
@@ -21,7 +20,7 @@ function CourseTabsNavigation({
             <a
               key={slug}
               className={classNames('nav-item flex-shrink-0 nav-link', { active: slug === activeTabSlug })}
-              href={`${getConfig().LMS_BASE_URL}${url}`}
+              href={url}
             >
               {title}
             </a>
@@ -34,6 +33,7 @@ function CourseTabsNavigation({
 
 CourseTabsNavigation.propTypes = {
   activeTabSlug: PropTypes.string,
+  className: PropTypes.string,
   tabs: PropTypes.arrayOf(PropTypes.shape({
     title: PropTypes.string.isRequired,
     priority: PropTypes.number.isRequired,
@@ -45,6 +45,7 @@ CourseTabsNavigation.propTypes = {
 
 CourseTabsNavigation.defaultProps = {
   activeTabSlug: undefined,
+  className: null,
 };
 
 export default injectIntl(CourseTabsNavigation);

src/course-header/Header.jsx

@@ -68,7 +68,13 @@ export default function Header({
 }
 
 Header.propTypes = {
-  courseOrg: PropTypes.string.isRequired,
-  courseNumber: PropTypes.string.isRequired,
-  courseTitle: PropTypes.string.isRequired,
+  courseOrg: PropTypes.string,
+  courseNumber: PropTypes.string,
+  courseTitle: PropTypes.string,
+};
+
+Header.defaultProps = {
+  courseOrg: null,
+  courseNumber: null,
+  courseTitle: null,
 };