docker hub compatible ARM build

[diginc]

Tweaked the docker file from #30 (sorry it got reverted during an earlier merge/revert mishap)

Example of running it on a RPI2:

pi@raspberrypi:~ $ docker run -p 53:53/tcp -p 53:53/udp -p 80:80 --cap-add=NET_ADMIN -e ServerIP="$IP" -it -d diginc/pi-hole:arm_dev                                                                                                                            
286c4f2372bc5b29c74a3e46cc2dab54eda4e12b5e44362421edc5ec6b4ed320
pi@raspberrypi:~ $ host pi.hole localhost                                                                                                                                                                                                                       
Using domain server:
Name: localhost
Address: 127.0.0.1#53
Aliases: 

pi.hole has address 192.168.41.60
pi@raspberrypi:~ $ host archive.org localhost
Using domain server:
Name: localhost
Address: ::1#53
Aliases: 

archive.org has address 207.241.224.2
archive.org mail is handled by 100 mail.archive.org.

pi@raspberrypi:~ $ docker logs serene_agnesi 
Added ENV to php:
                        "VIRTUAL_HOST" => "192.168.41.60",
                        "ServerIP" => "192.168.41.60",
Using default DNS servers: 8.8.8.8 & 8.8.4.4
dnsmasq: syntax check OK.
Syntax OK
:::
::: You are root.
::: Neutrino emissions detected...
:::
::: No custom adlist file detected, reading from default file... done!
:::
::: Existing pihole directory found
:::
::: Getting raw.githubusercontent.com list... List updated, transport successful!
::: Getting adblock.gjtech.net list... List updated, transport successful!
::: Getting mirror1.malwaredomains.com list... List updated, transport successful!
::: Getting sysctl.org list... List updated, transport successful!
::: Getting zeustracker.abuse.ch list... List updated, transport successful!
::: Getting s3.amazonaws.com list... List updated, transport successful!
::: Getting s3.amazonaws.com list... List updated, transport successful!
::: Getting hosts-file.net list... List updated, transport successful!
::: Getting raw.githubusercontent.com list... List updated, transport successful!
::: Getting ransomwaretracker.abuse.ch list... List updated, transport successful!
::: 
::: Aggregating list of domains... done!
::: Formatting list of domains to remove comments.... done!
::: 120747 domains being pulled in by gravity...
::: Removing duplicate domains.... done!
::: 96796 unique domains trapped in the event horizon.
::: Formatting domains into a HOSTS file...
:::
::: Adding 10 adlist sources to the whitelist... done!
::: Running whitelist script to update HOSTS file.... 8 domains whitelisted!
::: Running blacklist script to update HOSTS file.... 0 domains blacklisted!
:::
::: Cleaning up un-needed files... done!
:::
[ ok efresh lists in dnsmasq...[....] Starting DNS forwarder and DHCP server: dnsmasq.
 done!
[ ok ] Starting web server: lighttpd.
==> /var/log/lighttpd/access.log <==
tail: unrecognized file system type 0x794c7630 for ‘/var/log/lighttpd/access.log’. please report this to bug-coreutils@gnu.org. reverting to polling

==> /var/log/lighttpd/error.log <==
2016-09-01 01:17:41: (log.c.164) server started 
tail: unrecognized file system type 0x794c7630 for ‘/var/log/lighttpd/error.log’. please report this to bug-coreutils@gnu.org. reverting to polling

==> /var/log/pihole.log <==
Sep  1 01:17:41 dnsmasq[264]: started, version 2.72 cachesize 10000
Sep  1 01:17:41 dnsmasq[264]: compile time options: IPv6 GNU-getopt DBus i18n IDN DHCP DHCPv6 no-Lua TFTP conntrack ipset auth DNSSEC loop-detect
Sep  1 01:17:41 dnsmasq[264]: using nameserver 8.8.4.4#53
Sep  1 01:17:41 dnsmasq[264]: using nameserver 8.8.8.8#53
Sep  1 01:17:41 dnsmasq[264]: read /etc/hosts - 7 addresses
tail: unrecognized file system type 0x794c7630 for ‘/var/log/pihole.log’. please report this to bug-coreutils@gnu.org. reverting to polling
Sep  1 01:17:44 dnsmasq[264]: read /etc/pihole/gravity.list - 96798 addresses
Sep  1 01:17:44 dnsmasq[264]: query[A] pi.hole from 172.17.0.1
Sep  1 01:17:44 dnsmasq[264]: /etc/pihole/gravity.list pi.hole is 192.168.41.60
Sep  1 01:17:44 dnsmasq[264]: query[AAAA] pi.hole from 172.17.0.1
Sep  1 01:17:44 dnsmasq[264]: forwarded pi.hole to 8.8.4.4
Sep  1 01:17:44 dnsmasq[264]: forwarded pi.hole to 8.8.8.8
Sep  1 01:17:44 dnsmasq[264]: reply pi.hole is NODATA-IPv6
Sep  1 01:17:44 dnsmasq[264]: query[MX] pi.hole from 172.17.0.1
Sep  1 01:17:44 dnsmasq[264]: forwarded pi.hole to 8.8.4.4
Sep  1 01:17:49 dnsmasq[264]: query[A] archive.org from 172.17.0.1
Sep  1 01:17:49 dnsmasq[264]: forwarded archive.org to 8.8.4.4
Sep  1 01:17:49 dnsmasq[264]: reply archive.org is 207.241.224.2
Sep  1 01:17:49 dnsmasq[264]: query[AAAA] archive.org from 172.17.0.1
Sep  1 01:17:49 dnsmasq[264]: forwarded archive.org to 8.8.4.4
Sep  1 01:17:49 dnsmasq[264]: reply archive.org is NODATA-IPv6
Sep  1 01:17:49 dnsmasq[264]: query[MX] archive.org from 172.17.0.1
Sep  1 01:17:49 dnsmasq[264]: forwarded archive.org to 8.8.4.4