Started on the UI project

Added ReactiveUI, Material design and MahApps
Added the welcome page

src/Artemis.Storage/StorageContext.cs

@@ -0,0 +1,28 @@
+using Artemis.Storage.Entities;
+using Microsoft.EntityFrameworkCore;
+
+namespace Artemis.Storage
+{
+    internal class StorageContext : DbContext
+    {
+        internal DbSet<Profile> Profiles { get; set; }
+        internal DbSet<Setting> Settings { get; set; }
+
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.UseSqlite("Data Source=Storage.db");
+        }
+
+        #region Overrides of DbContext
+
+        protected override void OnModelCreating(ModelBuilder modelBuilder)
+        {
+            // Composite keys must be configured with fluent API in Core
+            modelBuilder.Entity<Layer>().HasKey(l => new {l.ProfileId, l.Name});
+
+            base.OnModelCreating(modelBuilder);
+        }
+
+        #endregion
+    }
+}