BottleVersion: add imap-uw style versions

Library/Homebrew/bottle_version.rb

@@ -37,6 +37,10 @@ class BottleVersion < Version
     m = /-(\d{8})/.match(stem)
     return m.captures.first unless m.nil?
 
+    # e.g. 2007f from imap-uw-2007f.yosemite.bottle.tar.gz
+    m = /-(\d+[a-z])/.match(stem)
+    return m.captures.first unless m.nil?
+
     super
   end
 end

Library/Homebrew/test/test_bottle_versions.rb

@@ -60,4 +60,9 @@ class BottleVersionParsingTests < Homebrew::TestCase
     assert_version_detected '13-2.9.19',
       'libpano-13-2.9.19_1.yosemite.bottle.tar.gz'
   end
+
+  def test_imapuw_style
+    assert_version_detected '2007f',
+      'imap-uw-2007f.yosemite.bottle.tar.gz'
+  end
 end