Add placeholder text in process type select control

Refs #730

ng2-components/ng2-activiti-processlist/src/components/activiti-start-process.component.html

@@ -5,6 +5,7 @@
     <div class="mdl-dialog__content">
         <div class="mdl-textfield mdl-js-textfield alf-mdl-selectfield">
             <select name="processDefinition" [(ngModel)]="processDefinitionId" id="processDefinition">
+                <option value="" selected="selected">{{'START_PROCESS.DIALOG.TYPE_PLACEHOLDER'|translate}}</option>
                 <option *ngFor="let processDef of processDefinitions" [value]="processDef.id">
                     {{processDef.name}}
                 </option>

ng2-components/ng2-activiti-processlist/src/components/activiti-start-process.component.spec.ts

@@ -80,13 +80,13 @@ describe('ActivitiStartProcessButton', () => {
     it('should display the correct number of processes in the select list', () => {
         fixture.detectChanges();
         de = fixture.debugElement.query(By.css('select'));
-        expect(de.children.length).toBe(2);
+        expect(de.children.length).toBe(3);
     });
 
     it('should display the correct process def details', (done) => {
         fixture.detectChanges();
         fixture.whenStable().then(() => {
-            de = fixture.debugElement.query(By.css('select option'));
+            de = fixture.debugElement.queryAll(By.css('select option'))[1];
             let optionEl: HTMLOptionElement = de.nativeElement;
             expect(optionEl.value).toBe('my:process1');
             expect(optionEl.textContent.trim()).toBe('My Process 1');

ng2-components/ng2-activiti-processlist/src/i18n/en.json

@@ -45,6 +45,7 @@
                 "TYPE": "Type",
                 "NAME": "Name"
             },
+            "TYPE_PLACEHOLDER": "Choose one...",
             "ACTION": {
                 "START": "Start",
                 "CANCEL": "Cancel"