updated requirements.txt

Author: iscai-msft

requirements.txt

@@ -4,7 +4,7 @@ azure-cognitiveservices-language-textanalytics
 azure-cognitiveservices-search-autosuggest
 azure-cognitiveservices-search-customsearch
 azure-cognitiveservices-search-entitysearch
-azure-cognitiveservices-search-imagesearch
+azure-cognitiveservices-search-imagesearch>=1.0
 azure-cognitiveservices-search-newssearch
 azure-cognitiveservices-search-videosearch
 azure-cognitiveservices-search-visualsearch