Adds missing dash

Author: JJ

shippable.yml

@@ -5,5 +5,5 @@ build:
     - apt-get update && apt-get install rakudo-pkg-for-doc
     - curl -L https://cpanmin.us | perl - App::cpanminus && cpanm TAP::Formatter::JUnit
     - PATH="/opt/rakudo-pkg-for-doc/bin:/opt/rakudo-pkg-for-doc/share/perl6/site/bin:$PATH"
-    - P6_DOC_TEST_VERBOSE=1 prove -timer --formatter=TAP::Formatter::JUnit -e perl6 t | tee shippable/testresults/doctests.xml
+    - P6_DOC_TEST_VERBOSE=1 prove --timer --formatter=TAP::Formatter::JUnit -e perl6 t | tee shippable/testresults/doctests.xml