Added highlight for the COPY instruction

Docker-DCO-1.1-Signed-off-by: Asbjorn Enge <asbjorn@hanafjedle.net> (github: asbjornenge)

contrib/syntax/textmate/Docker.tmbundle/Syntaxes/Dockerfile.tmLanguage

@@ -12,7 +12,7 @@
 	<array>
 		<dict>
 			<key>match</key>
-			<string>^\s*(ONBUILD\s+)?(FROM|MAINTAINER|RUN|EXPOSE|ENV|ADD|VOLUME|USER|WORKDIR)\s</string>
+			<string>^\s*(ONBUILD\s+)?(FROM|MAINTAINER|RUN|EXPOSE|ENV|ADD|VOLUME|USER|WORKDIR|COPY)\s</string>
 			<key>captures</key>
 			<dict>
 				<key>0</key>

contrib/syntax/vim/syntax/dockerfile.vim

@@ -11,7 +11,7 @@ let b:current_syntax = "dockerfile"
 
 syntax case ignore
 
-syntax match dockerfileKeyword /\v^\s*(ONBUILD\s+)?(ADD|CMD|ENTRYPOINT|ENV|EXPOSE|FROM|MAINTAINER|RUN|USER|VOLUME|WORKDIR)\s/
+syntax match dockerfileKeyword /\v^\s*(ONBUILD\s+)?(ADD|CMD|ENTRYPOINT|ENV|EXPOSE|FROM|MAINTAINER|RUN|USER|VOLUME|WORKDIR|COPY)\s/
 highlight link dockerfileKeyword Keyword
 
 syntax region dockerfileString start=/\v"/ skip=/\v\\./ end=/\v"/