Removes installing git RPM

 The centos golang image should have pure centos and golang stack,
 needed additional dependencies to be installed explicitly via
 application layers.

Author: navidshaikh

golang/centos7/Dockerfile

@@ -4,7 +4,7 @@ ENV GOPATH /go
 
 RUN yum -y update && \
     mkdir -p "$GOPATH/src" "$GOPATH/bin" && chmod -R 777 "$GOPATH" && \
-    yum -y install git golang && yum clean all
+    yum -y install golang && yum clean all
 
 ENV PATH $PATH:$GOPATH/bin