Fix awkward dependency error message (#1130)

pkg/app/app_test.go

@@ -3379,7 +3379,7 @@ releases:
 			upgraded:    []exectest.Release{},
 			deleted:     []exectest.Release{},
 			concurrency: 1,
-			error:       `in ./helmfile.yaml: "foo" has dependency to inexistent release "bar"`,
+			error:       `in ./helmfile.yaml: "foo" depends on nonexistent release "bar"`,
 			log: `processing file "helmfile.yaml" in directory "."
 first-pass rendering starting for "helmfile.yaml.part.0": inherited=&{default map[] map[]}, overrode=<nil>
 first-pass uses: &{default map[] map[]}
@@ -3421,7 +3421,7 @@ Affected releases are:
   baz (mychart3) UPDATED
   foo (mychart1) UPDATED
 
-err: "foo" has dependency to inexistent release "bar"
+err: "foo" depends on nonexistent release "bar"
 `,
 		},
 	}

pkg/state/create_test.go

@@ -46,7 +46,7 @@ func TestReadFromYaml(t *testing.T) {
 	}
 }
 
-func TestReadFromYaml_InexistentEnv(t *testing.T) {
+func TestReadFromYaml_NonexistentEnv(t *testing.T) {
 	yamlFile := "example/path/to/yaml/file"
 	yamlContent := []byte(`releases:
 - name: myrelease

pkg/state/state_run.go

@@ -160,7 +160,7 @@ func GroupReleasesByDependency(releases []Release) ([][]Release, error) {
 			for _, n := range r.Needs {
 				if _, ok := idToReleases[n]; !ok {
 					id := ReleaseToID(&r.ReleaseSpec)
-					return nil, fmt.Errorf("%q has dependency to inexistent release %q", id, n)
+					return nil, fmt.Errorf("%q depends on nonexistent release %q", id, n)
 				}
 			}
 		}