chore(ui): improve typescript definitions

ui/src/sources/components/KapacitorStep.tsx

@@ -38,7 +38,7 @@ interface Props {
   setError: (b: boolean) => void
   sources: Source[]
   onBoarding?: boolean
-  kapacitor: Kapacitor
+  kapacitor?: Kapacitor
   deleteKapacitor: sourcesActions.DeleteKapacitor
   setActiveKapacitor: sourcesActions.SetActiveKapacitor
   fetchKapacitors: sourcesActions.FetchKapacitorsAsync

ui/src/sources/containers/OnboardingWizard.tsx

@@ -98,7 +98,7 @@ class OnboardingWizard extends PureComponent<Props, State> {
             <SourceStep
               ref={c => (this.sourceStepRef = c)}
               setError={this.handleSetSourceError}
-              source={source}
+              source={source as Source}
               onBoarding={true}
               me={me}
               isUsingAuth={isUsingAuth}
@@ -114,7 +114,7 @@ class OnboardingWizard extends PureComponent<Props, State> {
             previousLabel="Go Back"
           >
             <DashboardStep
-              source={source}
+              source={source as Source}
               countSelected={this.countSelected}
               dashboardsCreated={dashboardsCreated}
               ref={c => (this.dashboardStepRef = c)}
@@ -131,9 +131,9 @@ class OnboardingWizard extends PureComponent<Props, State> {
             previousLabel="Go Back"
           >
             <KapacitorStep
-              ref={c => (this.kapacitorStepRef = c)}
+              ref={(c: any) => (this.kapacitorStepRef = c)}
               setError={this.handleSetKapacitorError}
-              source={source}
+              source={source as Source}
               onBoarding={true}
             />
           </WizardStep>