Remove "android:label" from the library's manifest

[gowong]

A library doesn't need an application label. Having one actually causes conflicts with the consumer application when merging the manifests.

Error:Execution failed for task ':app:processDebugManifest'.
> Manifest merger failed : Attribute application@label value=(@string/all_appname) from AndroidManifest.xml:15:9-44
	is also present at [agency.tango.android:avatar-view-glide:0.0.2] AndroidManifest.xml:13:9-41 value=(@string/app_name).
	Suggestion: add 'tools:replace="android:label"' to <application> element at AndroidManifest.xml:10:5-58:19 to override.

[mzielu]

@radzio #23