remove opam info msg from output

test/dry-run.t

@@ -1,6 +1,6 @@
 When --dry-run is used, exit code is 0
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"

test/error-no-node_module.t

@@ -1,6 +1,6 @@
 Errors when node_module folder is not found
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"

test/error-non-eq-filter.t

@@ -1,6 +1,6 @@
 Errors when using npm-version without an equality filter `=`
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"

test/error-version-not-match.t

@@ -1,6 +1,6 @@
 Errors when version does not match
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"

test/more-than-one-depext.t

@@ -1,6 +1,6 @@
 Supports package with more than one depext
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"

test/more-than-one-npm-in-list.t

@@ -1,6 +1,6 @@
 Supports having more than one npm package in the syspkg list
 
-  $ opam switch create . --empty
+  $ opam switch create . --empty | grep -v "to update the current shell environment"
 
   $ cat > test.opam <<EOF
   > opam-version: "2.0"