deps: remove covidcast dependency

Author: dshemetov

.Rbuildignore

@@ -1,3 +1,5 @@
+^renv$
+^renv\.lock$
 ^.*\.Rproj$
 ^\.Rproj\.user$
 ^data-raw$

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: epidatasets
 Title: Epidemiological Data for Delphi Tooling Examples
-Version: 0.0.2
+Version: 0.0.3
 Authors@R: c(
     person(c("Daniel", "J."), "McDonald", , "daniel@stat.ubc.ca", role = "aut"),
     person("Nat", "DeFries", , "ndefries@andrew.cmu.edu", role = c("cre", "aut")),
@@ -27,8 +27,7 @@ URL: https://github.com/cmu-delphi/epidatasets,
     https://cmu-delphi.github.io/epidatasets/
 Depends:
     R (>= 2.10)
-Suggests: 
-    covidcast,
+Suggests:
     data.table,
     dplyr,
     epidatr,