change egrep to grep -E

egrep is deprecated now, at least on my Linux box, so this was
spitting out tons of warning messages, which this change stops.

Author: ewollesen

Makefile

@@ -28,7 +28,7 @@ VERSION_PACKAGE:=$(REPOSITORY_PACKAGE)/application
 GO_BUILD_FLAGS:=-buildvcs=false
 GO_LD_FLAGS:=-ldflags '-X $(VERSION_PACKAGE).VersionBase=$(VERSION_BASE) -X $(VERSION_PACKAGE).VersionShortCommit=$(VERSION_SHORT_COMMIT) -X $(VERSION_PACKAGE).VersionFullCommit=$(VERSION_FULL_COMMIT)'
 
-FIND_MAIN_CMD:=find . -path './$(BUILD)*' -not -path './.gvm_local/*' -not -path './vendor/*' -name '*.go' -not -name '*_test.go' -type f -exec egrep -l '^\s*func\s+main\s*(\s*)' {} \;
+FIND_MAIN_CMD:=find . -path './$(BUILD)*' -not -path './.gvm_local/*' -not -path './vendor/*' -name '*.go' -not -name '*_test.go' -type f -exec grep -E -l '^\s*func\s+main\s*(\s*)' {} \;
 TRANSFORM_GO_BUILD_CMD:=sed 's|\.\(.*\)\(/[^/]*\)/[^/]*|_bin\1\2\2 .\1\2/.|'
 
 GO_BUILD_CMD:=go build $(GO_BUILD_FLAGS) $(GO_LD_FLAGS) -o