Merge pull request #3 from randomrng/master

added zlib1g-dev

docs/devs/building/unix.md

@@ -61,12 +61,14 @@ You will need a compiler and other tools that could be installed with `build-ess
 
 Also you will need a bunch of development libraries:
 
-	sudo apt-get install \
-	    libboost-date-time-dev \
-	    libboost-filesystem-dev \
-	    libboost-program-options-dev \
-	    libboost-system-dev \
+	sudo apt-get install << EOF
+	    libboost-date-time-dev
+	    libboost-filesystem-dev
+	    libboost-program-options-dev
+	    libboost-system-dev
 	    libssl-dev
+	    zlib1g-dev
+	EOF
 
 If you need UPnP support miniupnpc development library should be installed (don't forget to rerun CMake with needed option):