Update ubuntu

- `ubuntu:precise`: 20150212
- `ubuntu:trusty`: 20150218.1
- `ubuntu:utopic`: 20150211
- `ubuntu:vivid`: 20150218

library/ubuntu

@@ -4,27 +4,31 @@
 # see also https://wiki.ubuntu.com/Releases#Current
 
 # commits: (master..dist)
-#  - a9da4b3 Update tarballs
-#    - `ubuntu:precise`: 20150128
-#    - `ubuntu:trusty`: 20150128
-#    - `ubuntu:utopic`: 20150128
-#    - `ubuntu:vivid`: 20150127.1
+#  - 50d175c Update tarballs
+#    - `ubuntu:precise`: 20150212
+#    - `ubuntu:trusty`: 20150218.1
+#    - `ubuntu:utopic`: 20150211
+#    - `ubuntu:vivid`: 20150218
 
-# 20150128
-12.04.5: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c precise
-12.04: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c precise
-precise: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c precise
+# 20150212
+12.04.5: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd precise
+12.04: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd precise
+precise-20150212: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd precise
+precise: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd precise
 
-# 20150128
-14.04.1: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c trusty
-14.04: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c trusty
-trusty: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c trusty
-latest: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c trusty
+# 20150218.1
+14.04.2: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd trusty
+14.04: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd trusty
+trusty-20150218.1: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd trusty
+trusty: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd trusty
+latest: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd trusty
 
-# 20150128
-14.10: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c utopic
-utopic: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c utopic
+# 20150211
+14.10: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd utopic
+utopic-20150211: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd utopic
+utopic: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd utopic
 
-# 20150127.1
-15.04: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c vivid
-vivid: git://github.com/tianon/docker-brew-ubuntu-core@a9da4b3cd8977c2aacafe5d9d0056cbb360f2d1c vivid
+# 20150218
+15.04: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd vivid
+vivid-20150218: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd vivid
+vivid: git://github.com/tianon/docker-brew-ubuntu-core@50d175ca0b2820fcdb213455d46d1a47f11493cd vivid