If you go down to one pub in London today, you’ll be in for a big surprise. The charming Gunmakers in Clerkenwell, which is tucked down a cobbled road, has a hairdressers hidden in its attic so you can get a rum, coke and cut at the same time. I popped to the Gun Club salon on a rainy Wednesday afternoon, where I met the lovely Tim on the top floor. The attic salon has a nice chilled-out feel, and there is even a small bar with delicious banana-infused negroni mix waiting to be poured. I explained to Tim that I hadn’t had a haircut for more than three years, as self-beautification is botto...