scrubbed install assessment errors

app/controllers/assessments_controller.rb

@@ -88,18 +88,11 @@ def new
   def installAssessment
     ass_dir = Rails.root.join("courses", @course.name)
     @unused_config_files = []
-    flash[:error] = ""
     Dir.foreach(ass_dir) do |filename|
-      # assessment's yaml file must exist
-      if !File.exist?(File.join(ass_dir, filename, "#{filename}.yml"))
-        flash[:error] += "Yml does not exist: " + filename +"     -     "
-        next
-      end
+      next unless File.exist?(File.join(ass_dir, filename, "#{filename}.yml"))
+
       # names must be only lowercase letters and digits
-      if filename =~ /[^a-z0-9]/
-        flash[:error] += "Name must be only lowercase letters and digits: "+filename
-        next
-      end
+      next if filename =~ /[^a-z0-9]/
 
       # Only list assessments that aren't installed yet
       assessment_exists = @course.assessments.exists?(name: filename)