remove package atlas, because there's doesn't seem to be a way to get it working

src/atlas.mk

@@ -1,25 +0,0 @@
-# This file is part of mingw-cross-env.
-# See doc/index.html for further information.
-
-# ATLAS
-PKG             := atlas
-$(PKG)_IGNORE   :=
-$(PKG)_VERSION  := 3.8.3
-$(PKG)_CHECKSUM := c7546210df4796457d9e96a00444adc4c0f2e77f
-$(PKG)_SUBDIR   := ATLAS
-$(PKG)_FILE     := $(PKG)$($(PKG)_VERSION).tar.bz2
-$(PKG)_WEBSITE  := http://math-atlas.sourceforge.net/
-$(PKG)_URL      := http://$(SOURCEFORGE_MIRROR)/project/math-atlas/Stable/$($(PKG)_VERSION)/$($(PKG)_FILE)
-$(PKG)_DEPS     := gcc
-
-define $(PKG)_UPDATE
-    # seems to use even/odd development versioning
-endef
-
-define $(PKG)_BUILD
-    mkdir '$(1).build'
-    cd '$(1).build' && '$(1)'/configure \
-        --prefix='$(PREFIX)/$(TARGET)' \
-        --cc='$(TARGET)-gcc'
-    $(MAKE) -C '$(1).build' -j 1 install
-endef