Add some missing labels in Project Member modal

Almost all missing labels were added in commit
83787392042d23956e2ea4fbe6625092bf9160d1.
But, some were missed in the New User tab of the Add Member to Project
modal.

src/components/organisms/ProjectMemberModal/ProjectMemberModal.jsx

@@ -261,6 +261,7 @@ class ProjectMemberModal extends React.Component<Props, State> {
         name={field.name}
         type={field.type || 'string'}
         value={value}
+        label={field.label}
         onChange={onChange}
         width={StyleProps.inputSizes.large.width}
         disabled={this.props.loading}
@@ -278,18 +279,19 @@ class ProjectMemberModal extends React.Component<Props, State> {
     const userProjects = this.props.projects.map(p => ({ name: p.name, id: p.id }))
     const fields = [
       this.renderField(
-        { name: 'username', required: true },
+        { name: 'username', label: 'Username', required: true },
         this.state.username,
         username => { this.setState({ username }) }
       ),
       this.renderField(
-        { name: 'description' },
+        { name: 'description', label: 'Description' },
         this.state.description,
         description => { this.setState({ description }) }
       ),
       this.renderField(
         {
           name: 'Primary Project',
+          label: 'Primary Project',
           // $FlowIssue
           enum: [{ name: 'Choose a project', id: null }].concat(userProjects),
         },
@@ -298,22 +300,22 @@ class ProjectMemberModal extends React.Component<Props, State> {
       ),
       this.renderRolesField(),
       this.renderField(
-        { name: 'password', required: true },
+        { name: 'password', label: 'Password', required: true },
         this.state.password,
         password => { this.setState({ password }) }
       ),
       this.renderField(
-        { name: 'confirm_password', required: true },
+        { name: 'confirm_password', label: 'Confirm Password', required: true },
         this.state.confirmPassword,
         confirmPassword => { this.setState({ confirmPassword }) }
       ),
       this.renderField(
-        { name: 'Email' },
+        { name: 'Email', label: 'Email' },
         this.state.email,
         email => { this.setState({ email }) }
       ),
       this.renderField(
-        { name: 'Enabled', type: 'boolean' },
+        { name: 'Enabled', label: 'Enabled', type: 'boolean' },
         this.state.enabled,
         enabled => { this.setState({ enabled }) }
       ),