A couple weeks ago, I stumbled upon an adorable pop-up boutique full of feminine, flirty frocks. The best part? Everything in the store is under $200. The Fitzroy Boutique is open at 162 Cumberland St., but hurry!  The shop closes for the fall season tomorrow. Fitzroy Boutique was started by two friends, Angela Pastor and Julie Buczkowski.  Their pop-up concept was inspired by…