README: add libarchive prerequisite

Problem: README does not list libarchive build prerequisite.

Add libarchive to prerequisite table and os-specific package lists.

Author: garlick

README.md

@@ -50,6 +50,7 @@ czmq-devel        | libczmq-dev       | >= 3.0.1          |
 jansson-devel     | libjansson-dev    | >= 2.6            |
 libuuid-devel     | uuid-dev          |                   |
 lz4-devel         | liblz4-dev        |                   |
+libarchive-devel  | libarchive-dev    |                   |
 ncurses-devel     | libncurses-dev    |                   |
 hwloc-devel       | libhwloc-dev      | >= v1.11.1        |
 sqlite-devel      | libsqlite3-dev    | >= 3.0.0          |
@@ -78,12 +79,12 @@ jq                | jq                |
 
 ##### Installing RedHat/CentOS Packages
 ```
-yum install autoconf automake libtool make pkgconfig glibc-devel zeromq4-devel czmq-devel libuuid-devel jansson-devel lz4-devel hwloc-devel sqlite-devel lua lua-devel lua-posix python36-devel python36-cffi python36-yaml python36-jsonschema python3-sphinx aspell aspell-en valgrind-devel mpich-devel jq
+yum install autoconf automake libtool make pkgconfig glibc-devel zeromq4-devel czmq-devel libuuid-devel jansson-devel lz4-devel libarchive-devel hwloc-devel sqlite-devel lua lua-devel lua-posix python36-devel python36-cffi python36-yaml python36-jsonschema python3-sphinx aspell aspell-en valgrind-devel mpich-devel jq
 ```
 
 ##### Installing Ubuntu Packages
 ```
-apt install autoconf automake libtool make pkg-config libc6-dev libzmq3-dev libczmq-dev uuid-dev libjansson-dev liblz4-dev libhwloc-dev libsqlite3-dev lua5.1 liblua5.1-dev lua-posix python3-dev python3-cffi python3-yaml python3-jsonschema python3-sphinx aspell aspell-en valgrind libmpich-dev jq
+apt install autoconf automake libtool make pkg-config libc6-dev libzmq3-dev libczmq-dev uuid-dev libjansson-dev liblz4-dev libarchive-dev libhwloc-dev libsqlite3-dev lua5.1 liblua5.1-dev lua-posix python3-dev python3-cffi python3-yaml python3-jsonschema python3-sphinx aspell aspell-en valgrind libmpich-dev jq
 ```
 
 ##### Building from Source