CRAN: address test failures

[aronatkins]

    ══ Failed tests ════════════════════════════════════════════════════════════════
    ── Error ('test-client-cloud.R:623:3'): findDeploymentTarget() results in correct Cloud API calls when given appId ──
    Error in `openssl::base64_decode(authInfo$secret)`: Failed to decode base64 string
    Backtrace:
        ▆
     1. └─rsconnect (local) configureTestAccount() at test-client-cloud.R:623:3
     2.   └─rsconnect::setAccountInfo(...) at test-client-cloud.R:120:5
     3.     └─rsconnect:::findShinyAppsAccountId(name, token, secret, server)
     4.       └─client$currentUser()
     5.         └─rsconnect:::GET(service, authInfo, "/users/current/")
     6.           └─rsconnect:::httpRequest(...)
     7.             └─rsconnect:::authHeaders(authInfo, method, path)
     8.               └─rsconnect:::signatureHeaders(authInfo, method, path, file)
     9.                 └─openssl::base64_decode(authInfo$secret)
    ── Error ('test-http.R:56:3'): authHeaders() picks correct method based on supplied fields ──
    Error in `openssl::base64_decode(authInfo$secret)`: Failed to decode base64 string
    Backtrace:
        ▆
     1. └─testthat::expect_snapshot(...) at test-http.R:56:3
     2.   └─rlang::cnd_signal(state$error)
    
    [ FAIL 2 | WARN 0 | SKIP 155 | PASS 616 ]
    Error: Test failures
    Execution halted

https://cran.r-project.org/web/checks/check_results_rsconnect.html
https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-clang/rsconnect-00check.html
https://www.r-project.org/nosvn/R.check/r-devel-linux-x86_64-debian-gcc/rsconnect-00check.html

[aronatkins]

Likely related: jeroen/openssl#131

[aronatkins]

https://github.com/jeroen/openssl/blob/5cb84333f9da1178d897774836a5734c9dd69de2/src/base64.c#L45-L49

[aronatkins]

The underlying cause was the use of simple strings as test data that needed to be Base64 encoded.